I've learned how to sleep on airplanes. When I'm taking a trans-Atlantic flight or going to a different continent, I will always read because reading puts me to sleep. When you watch a movie, you have all that light coming to your eyes, but with reading, I can't get through 15 or 20 pages.

Sometimes I think the easiest way to introduce what goes into managing the expenses of a tennis career is to take a look at another pro sport and notice some of the differences.

My expenses are largely a fixed, sunken cost, regardless of how much revenue I earn.

Usually I'm traveling for tennis, so the most important thing for me is to not get jet lag.

I want to be a top-10 player and I want to win a Grand Slam tournament.

A tournament pays me to show up because the fans want to see me and I move the needle at the box office? That's amazing. It's good for tennis, good for me and good for the event. If a sponsor wants to pay to put their company name on my shirt because they think I'm a strong ambassador for their brand? Heck yes.

I felt a ton of pressure in '08. A lot of great things were expected of me right out of the gate, and I brought some of that on myself with those great early results. But I wasn't a good enough player to make a run every fourth or fifth tournament. I wasn't as good a player as my ranking indicated.

Up until I was a junior at Georgia, I felt that when all was said and done, I'd at least have a college degree to fall back on when tennis was finished.

You're going to lose points and gain points throughout the year.

That's why I enjoy Davis Cup, and I really enjoyed college tennis. It's very special. You want to go out there and compete your hardest, because you don't want to let anyone down. You want to absolutely give it your all for your team. And that's sort of the mentality I've taken to pro tennis.

I've sort of always pulled for the heels, like the bad guys. So I think if I were a pro wrestler, first I'd need to bulk up, and second I'll need to get sort of a bad-boy persona.

The good wins are still great, and you are on cloud nine when that happens, but the losses sting.

As a tennis player, or any professional athlete, our career has a shelf life. I don't want to waste any opportunities, I don't want to look back on it when I'm 45 and think I could have done a lot more.

Nothing against the Olympics. I played in 2012 and it was an incredible experience. It's different for tennis players than for swimmers and track and field athletes. That's the pinnacle of their sport and not so much the pinnacle of tennis.

For many years, tennis was the most important thing in my life. That was great. Nothing wrong with that.

I think the more matches that I play, the better shape I'm going to get in. That's the best type of fitness you can do.

I always have to play very aggressive on the court. It's something that's easier said than done.

My theory is that I'm just closer to the sun than everyone else. I weigh more than everyone else, I'm taller than everyone else. When it's really humid and hot outside it's going to take a bigger toll on me.

It's very important to be rested.

The hardest part about traveling for work is that I'm a big guy, so traveling is sometimes uncomfortable for me.

People think when you're struggling and not winning matches it's because you're not working hard. That's the biggest misnomer in tennis.

Everything has gone pretty fluidly in my personal life, so I think that certainly helps.

If someone had told me at fourteen that I'd be six-ten, I might have stuck with basketball, in all seriousness.

There are a lot of things that go on between the lines of a tennis court, mentally, physically and whatnot.

I've done a good job putting some meat on my bones since my freshman year of college. It's taken a lot of work. I was just under 200 pounds my freshman year; I was 6'8' and 198 pounds.

I try not to make a habit of spending the whole year losing in the first rounds of events, but tennis is one of those sports where nothing is guaranteed.

You know, Slams are tough. It's the most physical, in my opinion. You're playing three out of five.

I always knew that my best tennis was going to be in my late 20s.

The best part about traveling for work is that it's better than sitting behind a desk!

A big upper body is not a great thing for tennis, and for me, flexibility is important.

When I left college, I just thought I could play tennis to delay getting a regular job and go there and try to make ends meet. But it's been a very different experience for me, fortunately.

Taking care of my body and my health is my full-time job.

A lot of players have had it worse than me. Look at a guy like Andy Roddick, incredible Hall of Fame player, but he ran up against Roger so many times in big finals.

Davis Cup is a completely different animal.

I have a coach and I have a chiropractor, who works to keep me healthy. I pay their salaries. I pay for their flights as we travel around the world on a weekly basis, and I pay for their hotels and meals while we're on tour.

Tennis is a funny sport.

A lot of times when I'm confident and relaxed on the court, I'm going to be a pretty tough out. But when I'm not so confident and not so relaxed, I tense up and my balls fall short and everything. It just sort of unravels.

When I fly overseas, I usually fly business class. If not, my knees are going to be at my chin.

I've played with Prince racquets my entire career.

What I most look forward to about traveling to MEMPHIS is the great food.

In the past, I've played where I only just rely on my serve.

My family and friends, they know that I'm a really good competitor.

Probably the most infamous story in our family: My oldest brother took a U-lock bike lock and locked my head to the bedpost. And he didn't just do this for a minute or two; he did this for a couple hours. I was maybe 8 or 9, and he was maybe 15.

Any time you get to come to New York and be near New York City, that is a very cool opportunity.

We never got much in the way of material things, but if you can be spoiled by good cooking, my mom spoiled me three times a day all my life.

Our biggest events are the Grand Slams and are always going to be the Grand Slams.

I try not to eat too much, but I always get hungry before a match. I make sure I have enough fuel in my body. I'll eat pasta and a little bit of protein usually. I'm pretty much eating a full meal.

Outdoor tennis plays into my strengths a little better.

There is so much that goes in to being a good tennis player. It's not just what you can do well on the court, it's between the ears as well.

I love building a team around me, and being able to support a group of people is one of the best feelings I've come to know during my career; I imagine this is what a lot of business owners can relate to this.