HAHAHA, my friends at school work for campus grounds maintanence. They are always finding random shit... especially weed bags. They find 2-3 gram's per day. I guess they sell them off to random people for safety reasons.

Also, I found a bag in the cafeteria, gave it to a friend who may have smoked it.

... God I can't wait to get back.

Good luck with your lost bag though.