Rafael Nadal still lives in a wing of his family's large, modern seafront home with its own bedroom, sitting room and bathroom.
He says his family and support team "cocoon me from the dangerously distracting hurly-burly that comes with money and fame, and create the environment of affection and trust I need to allow my talent to flower. To imagine my good fortune and success in their absence is to imagine the impossible".
Nadal's mother Ana Maria Parera
"Deep down, he is a super-sensitive human being full of fears and insecurities that people who don't know him would scarcely imagine," says Ana Maria. "He doesn't like the dark, for example, and he prefers to sleep with the light, or the TV, on. He is not comfortable with thunder and lightning, either. When he was a child he'd hide under a cushion when that happened and, even now, when there's a storm and you need to go outside to fetch something, he won't let you.
"And then there are his eating habits, his loathing of cheese and tomato, and of ham, the national dish of Spain. I'm not as mad about ham myself as most people seem to be, but cheese? It is a bit peculiar.
"He's a prudent driver," she adds. "He accelerates, brakes, accelerates, brakes, and he is awfully careful about overtaking, however powerful his car might be. If I take the car to drive to Palma, only an hour away, he'll beg me, always, to drive slowly and carefully.
"I like to light up the fireplace almost every night. If he goes out, he'll remind me before leaving to put out the fire before I go to sleep. And then he'll phone three times from whatever restaurant or bar he is in to make sure I've done so."
Nadal's girlfriend since 2005, Maria Francisca Perelló
"Travelling together everywhere, even if I could, would not be good either for him or for me," says Maria Francisca, who has a degree in business administration and a full-time job with an insurance company in Palma, Mallorca. "He needs his space when he is competing, and just the idea of me hanging around waiting on his needs all day wears me out. It would asphyxiate me. And then he would have to be worrying about me … No. If I followed him everywhere, I think there's a risk we might stop getting along."
She remembers a time when they were in Paris and he had to go to a dinner hosted by one of his sponsors. "He asked me if I wanted to go, but I chose not to," she says. "I stayed in our hotel. When Rafael got back he said, 'Thank God you didn't come'. The place had been swarming with photographers. For me to have gone would have meant stepping into that celebrity world. It's not a world I want to be part of, nor do I think Rafa would have chosen to be with a woman who looked for that in life.
"Even if my family asks me about Rafael," she adds, "I prefer not to say much. The fact is that I just don't feel comfortable talking about these things, even in private. It's what works for me, and what works for Rafael and me as a couple. We wouldn't have it any other way."
Nadal's sister Maribel, five years his junior
"One time when he was away in Australia my doctor ordered me to have some tests done – nothing too serious – but in all the messages I exchanged with Rafael that was the one thing I didn't mention. It would freak him out; it would risk throwing him completely off his game," says Maribel, whose pride in her brother's achievements does not blind her to "the truth", expressed with teasing affection, that he is "a bit of a scaredy cat".
"He's always talking about buying himself a boat. He loves fishing and jet-skiing, but he won't jet-ski, nor will he swim, unless he can see the sand at the bottom. Nor will he ever dive off a high rock into the sea, as his friends do all the time.
"Most boys growing up see their younger sisters as irritations," she adds, "especially when they are teenagers but that has never been the way Rafael has treated me. He's always urged me to come along when he goes out with his friends. It's natural to us, even if others might sometimes find it strange, and it's part of the secret of our special bond."
- These are edited extracts from 'Rafa: My Story' by Rafael Nadal with John Carlin, published by Sphere (RRP £17.99). It is available from Telegraph Books for £16.99 plus £1.25 p&p. Please call 0844 871 1515 or go to books.telegraph.co.uk