Chic frontman Nile Rodgers survives on only two or three hours of sleep a night.
The 60-year-old musician went to a sleep clinic when he was five years old to be treated for what doctors then thought was insomnia.
However, the medics soon realised young Rodgers was not sleep deprived at all but in fact "very aware".
"I only sleep two to three hours a night, maybe if I'm exhausted I'll sleep four, and the rare occasion I sleep five," he said.
"I feel like Rip Van Winkle. I just don't sleep, I don't need it - I've never needed it. I function very well, I'm 60-years-old and I feel great."
The Chic guitarist remembers tests being done on him at the sleep clinic and says he always felt fine.
He added: "After a week some learned young doctor said: 'Nile how to you feel?' and I said 'I feel great'. He said: 'Go home! You'll live a third longer than everybody else'!"
The star was diagnosed with extremely aggressive prostate cancer in 2010, but is now cancer-free and feeling healthy.
Chic Featuring Nile Rodgers will support Lionel Richie and Jennifer Lopez on the main stage at the British Summertime festival at Hyde Park today.