It was always the same whenever you were doing an exam, wasn't it?. The former Wimbledon champion Andre Agassi has withdrawn from this year's tournament because of injury. All England Club officials said yesterday that the 1992 champion said in a fax that he would not play in the tournament, which starts next Monday. It has to be today.Nick Bollettieri will be writing for The Independent throughout Wimbledon. I've known that ever since my brother, Jimmy, died in a freak accident, aged 14 Do what you believe in But do it today. But still you have to treat every day as though it's the only one that counts That's what drives me Life can be gone in a fraction of a second. I want the best from myself, I want the best from my students.

I want them, like me, to give every hour of every day to their goals.I'm 74 next month, which I figure means I have perhaps only 50 more years at the frontline. I had to sell my academy to IMG in 1987 because I was going bust, I'd given too many scholarships Do I regret that? Never. Andre? Jeez, I thought: "Will he even show up today? And what will he wear?" But I got to know what made each of them tick and I wound it up.I'm a lousy businessman. Jim was a workhorse, a battler.Monica, the Postage Stamp, stuck until she got there, practising a single shot for 12 hours at a time. David's mom was a born-again Christian who stood on the sidelines and prayed on every shot.

Different because no two players are alike.At one point my resident students included David Wheaton, who rose to be world No 12, and Jim Courier, Monica and Andre, who all made No 1. And the coach needs to be adaptable too, to address the paradox of needing to treat every student differently, but every one the same.The same in terms of attention and detail, whether they have $50m in the bank or zilch. It makes you a more effective teacher.So to adaptability, for player and coach alike Champion athletes have bad days and still win The right training, to breaking point at times, helps. "No, not really," I replied."Well you should try it," he said "You might learn something." I tried it I learnt. "Have you ever listened to anyone in your life?" he once asked me. How else can I explain why Serena Williams chose to come to me for a week before each of her five Grand Slam wins in 2002 and 2003? What could I teach her, one of two of the finest female athletes in history (the other is Venus) about playing tennis, except advising a bit of work on her serve, her volleys? She arrived saying she was tired of being No 2, I convinced her it didn't have to be that way.Accepting support is crucial and I now know how best to be supportive You listen Andre taught me that way back.