I would say the dumbest ever event for me happened one night around 7pm. I was waiting to go to the movies with a group of people. Me and the other guy wanted to smoke before but didn't want to go far because we would miss the ride. He had a blunt of chronic and we walked as far away from the group as we could get but still see them. This put us right at the doors of the cafeteria -- which closes in 5 minutes. We light up and start passing this back and forth. Slowly a steady stream of people start coming out the door. We got a lot of strange looks but no one said anything. It was dumb as hell.
I working the info booth at a Festival once. A guy comes up and asks if I know where he can buy some weed. I say "No, but you can smoke this joint with me." So we are toking up and a cop walks up. (He was just coming on shift and just wanted to check in with Festival HQ.) We see him about 20 ft. away, so I hold the burning joint beneath the table, where he can't see it and chat with the cop for a few minutes. Cop walks away. We finish the joint.
At my old high school, we would smoke behind the shop class in the huge bush you could literally walk into. It was great.