Oh, I've seen plenty of people fuck up their lives with speed.
Here's where I'm coming from:
Until I was 17, I had always been for the most part anti-drug. Sure, I smoked pot a handful of times, got drunk at punk shows, but I was always resiliant and didn't get hangovers. A bunch of my friends snorted crank, and a few rolled every now and then, but that was it. See, these people, in my opinion, had problems. They were dysfunctional to start with, and methamphetamine and breaking into cars and houses didn't seem to be a productive thing to do.
I had my alcohol.
Fast-forward to Thanksgiving 1998, when I was at a friend's birthday party. I proceeded to get stinking, falling down drunk, try to fuck any available female I could focus my eyes on, and made an idiot of myself. I vomited on the last roll of toilet paper.
When I came to the next day, the only people left in the apartment were junkies. They got me coffee, and I spent the day hanging out with these people who weren't evil. They didn't go through my wallet while I was passed out or steal my shoes. Two of them were unemployed, one of them worked at a gas station, but the important thing was these people were functioning. My drinking, something that I thought was harmless, turned into a destructive habit, and something that I had always assumed would ruin your life was being used by the nicest goddamn people I'd met in recent memory.