Neil Young has an autobiography out, which I haven't read. I reviewed a massive biography of the rock star a decade ago for the first issue of The American Conservative (happy 10th anniversary), so I'll just repeat my diagnosis of the self-confident singer:
The secret to Young's career longevity appears to be that his health has steadily improved with age. Today, the superior physical and mental constitution he inherited from his mother Rassy, a tomboy champion amateur golfer, and his sportswriter father Scott, hard-working author of 30 books, is no longer dragged down by the polio, epilepsy, and drug abuse of his younger years. He now lifts weights, works out aerobically, and plays a lot of golf. Of course, some might argue that after hoovering up all that cocaine before his second marriage in 1978, a naturally robust individual like Young sends the wrong message about the danger of drugs to the mediocre masses simply by not being dead by now.
In short, Young is by nature a jock. But, a sickly youth diverted him into the arts at a propitious moment (the mid-1960s), where he's gotten a lot accomplished, although perhaps more by masculine force of will than by supreme talent.