The time your game is most vulnerable is when you're ahead; never let up.
There's a lot of ingredients go into being a good tennis player.
Each match is a huge effort from a physical point of view. You can only hit so many balls before your elbow or some part of your body is going to say, 'Hey, don't do that to me.'
Players who win on a clay surface are those who can control the ball, playing steadily and accurately from the back-court, keeping the ball in play and moving it around with changes of speed and spin, and resisting the temptation to over-hit.
Forty years ago, the players were like a travelling circus - we went everywhere together and were pretty good friends.
We were pretty darn good - fit and ready to play - but today's level is different. Those ground strokes are ever so much faster, coming back at you at a pretty good speed. Footwork-wise, you've got to be ready to hit that next shot. It's a tough time.
As a tennis player, you have a record, and that is what counts. I feel like I enjoyed myself, and I'm proud of what I accomplished.
It occurred to me that it would benefit me to play without emotion - well, without emotion others could see, anyway. Card players profited from having a poker face so opponents wouldn't know how good or bad their hand was, and I figured a deadpan expression would work in tennis, too.
I wasn't embarrassed that I'd had a stroke, but I just didn't want people to think I was milking it or looking for sympathy. It happened, and I dealt with it. Afterwards, I tried to do what I could for other people who had strokes, speaking at hospitals that treated stroke victims.
Camaraderie builds. We travelled together to Rome, Paris, Wimbledon, the U.S., lots of places. In a way, I miss it right now. My opponents were also my best friends.
Looking back, in comparison, there wasn't that much that you could do with a wooden racket. In my day, the matches were certainly much less demanding physically.
I saw Kyrgios down in Australia. He played some very good tennis, won two or three matches, and has done the same here at Wimbledon. I think Australia's got a good prospect in Kyrgios.