One to a few months on a regular basis throughout one's life can recharge the spirit more effectively than taking a year off per century. If you don't hate your job, and your presence is actually valued at work, a leave of absence is one option that doesn't require hitting the reset button.
Don't 'ask' for it. 'Inform' your employer that you need some time off and that you're going to take advantage of this great opportunity to do the first nude ascent of Makalu or whatever; you'd be surprised how flexible employers become...if they don't already want to flush your ass. It's gonna be way cheaper for them to figure something out than to hire somebody new if the leave of absence is relatively short.
The trick is, of course, to keep your expenses reasonable throughout your life. A lot of younger folks blow a sizable chunk of their disposable income on booze and bling, particularly their ride. Fine if you're rolling on cash, but if you even need to think about priorities; say FU to Madison Ave and cut that shit down; even a modest income will support a month or more off per year unpaid if no kids are involved. And learn how to cook from scratch, for fucks sake.
Your cooworkers will invariably say "I wish I could afford to do that" as the glower at you, simmering with resentful admiration, but it's almost always more about making choices rather than not having enough.