I'm Serena Williams on the court, but away I have so many different names. I call myself Butterfly.

I feel like I'm really young and I'm only thinking about my career and continuing playing.

It's remarkable she [Venus Williams] plays at all, given her Sjögren's syndrome [an autoimmune disorder that can cause joint pain]. She's back, winning tournaments. She didn't allow society to tell her, "You have this disease; you can't do that anymore." I look at her, like, "She's not playing at 100 percent. You are. You don't have excuses." Knowing what she went through helped me try to be a more positive person.

We're sisters, we're roommates, we're all that.

You just have to prove to yourself that you can go out there and be the best that you can be and not prove anything to anyone.

There are people who live, breathe and dress tennis.

I'm a perfectionist. I'm pretty much insatiable. I feel there's so many things I can improve on.