One person's personal experience:
So I'm sitting in a college class on the back row, as usual. I light up a cigarette -- This was back when you could actually smoke in public, anywhere, without anyone thinking twice about it. And it happens. This isn't the first time, either. I'm going to have to get up and leave this room, right now.
I walk the halls, trying to calm down a little bit. When I come back to class, my friend who's sitting next to me says, "You don't look so good." I know; my face is blanched and my hands are shaking.
I tell him about these episodes I've been having. He asks if I've been doing a lot of acid lately. I say, "No." And then he says something to me that was very important. Have you ever known a kid who was older than his years? A kid who was more like an old man trapped in a kid's body? That's the way it was with this guy.
Anyway, in all his great wisdom, he takes a long look at me and says, "Maybe you're just taking yourself too seriously."
I thought about that for the rest of the day, and do you know that I've not had anything like that happen to me since? And that was several years ago.