It's true. I don't think you come back from years of burning on that shit. I've seen speed freaks that looked really old, but never met any who actually were. That shit corrodes your brain about as much as long-term, hardcore alcohol abuse. Smoke pot, have a couple of beers, hell, even the occasional (unless, of course, your idea of an "occasion" is, say, lunch) line of coke or pinch of smack up your nose ain't gonna kill ya, or fuck you up too bad, and if you were doing pure methamphetamine four or five days a year, it probably wouldn't be that big a deal, either. I don't know and have never met anyone who enjoys doing crystal meth recreationally without abusing it to some extent. I'm not saying it can't be done, just that I've never seen it. The fry from meth is fucking hardcore, I've met plenty of people with burnt pool chemicals where their brain cells used to be.
