I smoked just about every day last semester before school. Mostly because it gave me that extra pep early in the day. I'm a physics major at a university, senior year, and I got just above a 3.0 gpa. Taking naps at school wasn't that uncommon when my high was fading but I had 2 hour gaps between classes.

Methinks the key is moderation and time management. Don't get stoned when you know you have shit to do.