George Carlin, heres a quote or 2...

Let's say I had a little baggie lying around the office. I'd get up, come over here, fuck around, shuffle a few papers, and all the while I'd be thinking about the pot. I'd say to myself, well... whatever I'm going to do today, it's obviously going to be more fun if I have a hit or two. But I got to the point where taking those hits made me feel dumber than I'd felt before."

"I'd wake up in the morning and if I couldn't decide whether I wanted to smoke a joint or not, I'd smoke a joint to figure it out. And I stayed high all day long. When people asked me, 'do you get high to go onstage?' I could never understand the question. I mean, I'd been high since eight that morning. Going onstage had nothing to do with it. When you're high, it's easy to kid yourself about how clever certain mediocre pieces of material are."