What's the worse experience you've ever had being a sub, whether it was your mistake or just the circumstances? Once long ago, when I first began subbing, I was subbing a kinder class. The babysitter of one of the students gave me some medicine that the child was supposed to take. Well, somehow I lost it throughout the course of the day. I should have sent the babysitter straight to the office to give it to the nurse to handle, but I didn't. I ended up having to tell the principal who was on the verge of having to call all the students' parents to let them know about missing medication that their kids could have gotten ahold of. But I ended up finding it in a place that the kids couldn't have even known about, but not before the principal knew about it! Darn! On top of that, the regular teacher said that I left the room messy, which wasn't true. I'm a neat freak. I think they just wanted to add fuel to the fire!