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.
The biographer I read was still shaking his head over how Young had taken over Crosby, Stills, & Nash at the height of their popularity through sheer brass.
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.