Relationships are give-and-take, and when you're a tennis player, you're certainly not giving. You have to be self-absorbed. It has to be about you.
“I'm so glad I'm not a dentist. How many times does someone say, 'Oh, Doc, it felt so good when you were drilling my teeth'? Never. But when you give someone a wonderful cookie, you put a little of yourself in, and you see someone's face light up - that's immediate approval.”