AP Photo

"I play tennis for a living even though I hate tennis, hate it with a dark and secret passion and always have." So writes Andre Agassi in his new autobiography, Open, published this week. It is 2006 and one of the world's most feted sports stars has just woken up in a New York hotel room, poised to play his last tournament.

But why would a great sportsman hate his sport? Why wouldn't he love everything about it and all it brings to his life – travel, glamour, money, mass adoration, endless free tennis rackets and barley water, not to mention the surely sustaining thought that he is doing something for a living that makes many of us sick with envy?