Well, let's make this thread something useful. What was the reason(s) you stopped, honestly. Was it interfering with your life, or do you have an addictive personality? It's nothing to be ashamed of at all, so pipe up.
The reasons I quit are pretty simple.
1. My future career will not tolerate it.
2. I just took out a bunch of student debt. I can't risk any sort of arrest.
3. I found that I'm just as happy with it as I am without it.
4. I put on 20lbs. I was a marthon runner before I started toking up. Next time I'll be more aware of my munchies. Damn munchies, killing my game.
That's my reasoning. I did quit to see what it was like, being off, and it's pretty much as it's reported to be. Non-addictive and non-habit forming (for the most part). I don't feel like I want it, though I'm sure I'll do it again before I get my degree.
A lot of people, like uber said, just realize that drug culture just isn't for them. It's really not tailored for my life choices, though I hold the drug in high regard and recommend it rather than alchohol, which leaves you a stumbling idiot at times.
I'm glad this didn't turn into a legalize cannabis thread. Too many of those.