That's something a lot of athletes miss - a lot of them walk away too soon. They don't get everything out of their system. They have a lot of what-ifs when they're sitting around later in life. I don't have that. I got all that out of my system. I pushed it to the brink, I loved it, and when I walked away, I'd had enough.

Bjorn was a different breed, I threw my best material at him, but he would never smile, but that added to the charm when he played me and Mac. We were going nuts and losing our mind and he was sitting back like he was on a Sunday stroll.

I don't go out there to love my enemy. I go out there to squash him.

There was never anything I wanted to do more than play tennis. Never once walked out there and thought, 'I wish I was doing something else.' Not once.

Greatest thing in life: Winning a tennis match. Second greatest thing in life: Losing a tennis match

From where we lived, to practise in St Louis was an hour-and-a-half drive each way, so that took a lot of the time. So really, our lives just took different paths.

I've been kicked in the teeth more times in tennis than the law ought to allow.