I'd calculated 1500 hours to make me a good-enough piano player. So I was interested to hear about this. 10,000 hours works out at six hours a day over five years. It makes sense. That's probably what Lennon and McCartney had from getting started with pianos and guitars in adolescence to writing I Wanna Hold Your Hand at 23 or 24.
And I suppose wee Mozart was putting in numerous hours per day at the keyboard whilst his pals were playing with toy soldiers. There's the story I heard about Hendrix, too, that he just practised at the guitar non-stop - he'd go out in the evening to the cinema wearing his guitar. Of course, I don't expect to have the ability of Mozart or The Beatles or Hendrix. And I don't have 10,000 hours at my disposal any more, (at an hour a day, that would take me to 80 years of age, which would mean I'd have difficulty qualifying for Young Musician of the Year). However, the view that ability takes only practice is very encouraging to my 1500 hours' scheme. I've probably done 30 hours now, about 2%.