Excerpted from What's Driving You??? How I Overcame Abuse and Learned to Lead in the NBA by by Keyon L. Dooling with Joel Canfield and Lisa CanfieldBook can be purchased online at Amazon.

When the lockout ended, I was still a Milwaukee Buck. Two weeks later, I was a Celtic. Boston needed a backup for Rajon Rondo, coming off his first All-Star season. I was more than happy to be picked for the job.

No NBA franchise has won as many championships as the Boston Celtics. And few are as respected and honored. I was once again part of one of the great organizations in basketball, just as I had been with the Heat.

Unbelievable.

It was my most incredible year as a pro. I got to play with some of the legends of the game – the kind of team I would have created for myself if I was playing NBA Live or NBA 2K on the Xbox. Kevin GarnettRay AllenPaul Pierce... they were all future Hall of Famers.

And then there was Doc Rivers.

He was one of three men in the NBA who were the most important to my development as a person and a player. Doc had an impact on players even if they didn’t ever play for him. All you had to do was just watch him, because he was a walking example of what you could be if you did things right.

What I loved about him was that he didn’t sweat the small things. If you didn’t want to practice in a shirt, you didn’t have to. If you wanted to listen to your music on the plane, you could go ahead. He wasn’t tripping off dress code or anything that didn’t impact the big picture.

But when you had a job to do in the weight room, on the court, in a professional setting? It was, “Do your f---ing job!”

That’s because he had only one team rule – and it only had one word in it: Respect. Respect your trainer’s time. You have a massage set up, be there on time. Respect the equipment guys’ job – don’t leave your stuff all raggedy, put it in the bin. The message was that people worked hard for us – and we should do our part to help them do what they did for us. Doc held you accountable.

Doc was consistent, he was passionate, he was compassionate, he was articulate, and he was tough. All you had to do was listen to his thunderous voice to know you didn’t mess. To me, he was everything that you would want to be as a man.

And as a coach. After an outstanding thirteen year run as an NBA player, he moved into coaching. He had been coaching for a little more than ten years when I joined the team. He had already won two Eastern Conference championships, and one NBA championship. He had also been NBA Coach of the Year and the NBA All-Star Game head coach twice. Today, he’s doing an incredible job with my first NBA team, the Clippers.

When I came to the Celtics, I was still deeply missing my Pop, even though it had been two years since he passed. I finally found a new father figure in Doc. When I needed guidance from an older man, someone who had more experience than me in life, Doc was there. I had been suffering without my dad’s wisdom, strength, and love, and Doc helped ease that pain with his leadership and skill.

He also gave the best pregame speeches I had ever heard in my life. It wasn’t the standard pep talk by any means. No, Doc would pull directly from his life experience and be honest and direct – as well as show his vulnerability. Many of his stories were about his father, who was a police officer, and the lessons he learned from him. He would take you on an emotional roller coaster, from the bottom to the top and back down again, and I would see these legendary basketball greats getting all pumped up. As for me, I would just try to contain myself; in the middle of one of his talks, I just wanted to yell, “Let me out there now! Please let me out there now! You don’t have to say anything else, Doc, just let me out there now!”

Maybe the most important aspect of his leadership was his use of the philosophy of Ubuntu, a South African term popularized by the iconic Nelson Mandela. Ubuntu doesn’t have one simple meaning, but it’s a word that signifies respect, unselfishness, sharing, and community. The idea is that, “In order for me to be all I can be, I need you to be all you can be – so that we can be all the best we can be.” Doc would say that if you applied Ubuntu in your house, at your job, in your community, in your county, if you apply it everywhere you go, you can impact the whole world and make it a better place.

How important was Ubuntu to the Celtics? Well, when Doc took the team to the 2008 NBA championship, that word was inscribed into their championship rings.

Getty Images

However, for most of the season, we were not allowed to say the word. Why? Because Doc would exclaim loudly, “We’re not there yet!” In other words, we had not achieved that bond as a team. I didn’t get it. I didn’t know why we couldn’t say it when the team had already been known for Ubuntu for the last four years.

It wasn’t until we were getting close to the playoffs that he finally thought we had achieved Ubuntu. I know I had. I gave myself to the team in a way I hadn’t since I played with Miami. I was through worrying about getting my next player contract; I was an older player and I just didn’t care anymore. I just wanted to do for the team. And Doc let me do just that in a way I had never been allowed before.

It began with my mentorship of Rajon Rondo. Before coming to Boston, I was a little wary of him. I had heard so many stories about how tough he was to work with and how hard he was to talk to – I just didn’t know what I was in for. His reputation was that he was standoffish, super smart, and super emotional – but, I had to say, these are the characteristics of many great men. Most great men, they hate authority and they hate the system and they’re very passionate about their beliefs, because they see a better way. Rondo was also a super-competitive guy: He wanted to win the drills, he wanted to win at playing checkers, heck, he even wanted to win at Connect Four. If you’ve ever seen the video of him taking down two ESPN guys in two separate games at once, you know what I’m talking about.

So here I was, on a mission to connect with this supposedly scary dude everyone’s talking about. I didn’t really have a choice, they even moved his locker next to mine to get the relationship going.

Result? A great friendship!

I found him to be the total opposite of scary. I think the timing had a lot to with it – he was at a place in life where he was open to my way of helping. There were a lot of misconceptions about him in the media and even in the league, and I wanted people to appreciate Ray (that’s what I call him) for who he truly was.

And who is he? An amazing player and an amazing guy. I can count on the fingers of one hand the number of NBA players that I seriously consider to be true friends that I can always depend on. Ray is one of them – a man of quality.

Getty Images

Unlike the Bucks, the Celtics were receptive to who I was as a person and allowed me to become the ultimate hype man. I was called the “emotional center” of the team by The Boston Globe – but I became that largely because Doc Rivers allowed me to be that person. It got to the point with him where, if he had a message to deliver to a player, I would be the guy to deliver it. He didn’t need to talk to them, he would just let me know what had to be communicated.

It began about halfway through the season. He would go, “Keyon! Rondo’s not here with us tonight, I need you to get him going.” Or, “Paul’s mind isn’t right. Turn him around.” Or, “Tell Kevin to get on the block, we need him to score.” He would say these things and just walk away. So, again – no choice for me. I had to get in there and tell all-time greats to do better!

While Doc was manning the huddle, I was left with the responsibility to tell these guys what he wanted from them. And somehow it worked. He knew they didn’t want to hear his voice all the time and that I had the years and the leadership quality that would make them want to listen to me. So he leaned on me. He’d say, “I need the bench ready when you come in!” – and I would run practice. We would do drills and make everyone go “game speed,” because when we go in, we need to go in together. These were fun times, fun times.

But nothing was more fun than flexin’.

Me and Marquis Daniels, another Florida boy, would do a goofy straight-up-and-down fist pump with both arms when we were warming the bench, to keep the team hyped during a game and to acknowledge a great play. It was no big thing. Then, late one night, a few of us were watching a game, something we would do on the road because we’d be too revved up from a game to sleep. One of my teammates noticed our moves, turned to me and said, ”KD, what was this you were doing when you were out there?” And I was like, “I don’t know. We were just flexin’ on them.”

It wasn’t anything all that spectacular, it was the kind of move you’d see in music videos and the like, but it suddenly caught on. We turned around and suddenly everybody in the stands at a home game was doing it! It grew to the point where the fans wanted an official name for it – and that’s how flexin’ was born. Last time I looked, it’s still going on in Boston to this day.

I just love to make a lasting impact.

Getty Images

That moment of doubt from last season, when I was in Milwaukee and my leadership was suddenly rejected? I was glad to see that moment was gone for good. I felt like I connected with Doc, with my teammates – and even with the media. I knew how to be engaging and give reporters what they wanted – but I also knew not to make it about me. I was about Ubuntu!

Here’s how an ESPN article saw it, written during the playoffs:

ATLANTA -- The question posed asked Celtics reserve guard Keyon Dooling about his two second-half 3-pointers that aided Boston's come-from-behind victory in Game 2 of an Eastern Conference quarterfinal series against the Hawks, the first of which snapped a 77-minute, 25-second trifecta-less streak for Boston to start the postseason.

Dooling politely tried to steer the conversation to the other end of the floor.

"We made some shots, but the key for us was defense," he said. "We really locked in, defensively. We were able to kinda slow [Atlanta point guard Jeff] Teague down—he’s like 'The Little Engine That Could,' he’s all over the place, but [Celtics guard] Avery [Bradley] did a good job of corralling him, our bigs did a good job of giving us extra shows...It was a defensive win for us."

Undeterred, the reporter asked again about the big shots. Keeping with his theme, Dooling got defensive.

"No, I heard your question," he said with a smile. "It’s not about what I did. It’s about our team and our defense."

And there in a nutshell is why coach Doc Rivers loves Dooling.

I guess it was.

As a player, I had a very uneven year, due to some hip and knee injuries. To tell you the truth, the shortened season was very hard on me physically and mentally; it was hard on all the players. We had to play a lot more games in a lot shorter window than normal to make up for lost time caused by the lockout. Come March of the season, however, I was taking it to the court again and ended up having some great playoff moments in the postseason.

But my biggest postseason moment ended up happening in the locker room.

It was Game 5 of the Eastern Conference semifinals against the Philadelphia 76ers. So far, the series was tied at 2–2, and at halftime, we were down 50-47. I could tell in the locker room that the guys were a little down and looking for me to say something the way I would before a game to get them feeling strong and positive.

I would do that by looking them in the eyes and saying something like, “I need you guys tonight. Everything you’ve got, I need it. Listen everybody, we’ve got a job to do. If your job is to cheer on the bench, I need you cheering! If your job is to play defense, damn it, defend! If your job is to rebound, you’d better rebound! I need you! I‘m with you, I’m two feet in and I’ll run through a wall right now for you! I’m all in, I don’t care about anything else but this team!”

And that was the spirit of what I had to say to them in the locker room that night at halftime. Yes, there was some language that you’d only find in an R-rated movie, but that was necessary to really pump those guys up.

After that halftime talk, we came back and crushed Philadelphia that night, 101-85. After the game, Brandon Bass told the media that the team had received "a sermon from Reverend Dooling" that turned it around.

From then on, that was my name – “The Reverend.” Even though I had said a lot of words you wouldn’t ever hear in any church, I wanted to raise their spirits just like a preacher and I guess I did just that.

Again, I saw what my true gifts were – and where my future path would take me. It was a sweet time, that Celtics year, my last full year in the NBA. We had a magnificent run; we made it all the way to the Eastern Conference Finals, where we lost Game 7 to my old team, the Heat. They went on to win the championship and good for them.

Being “promoted” to The Reverend was like my graduation from the NBA. It was the culmination of what I had tried to bring to the game, that kind of special energy that would enable everyone to do their best. I didn’t have a name to attach to that spirit until I played for Doc Rivers.

Ubuntu. It could truly make the world a better place if we all practiced it.