Please don't bite my head off...

I don't appreciate it. After spending a morning studying for neuropathology, I went to school for my afternoon class. I wasn't even in the school when the Dean asked me where I was this morning and why I wasn't in sport treatment. Well lets see, I thought sport treatment class started tomorrow, not today, my mistake. That would be why I wasn't in class. I apologized and turned to leave and he said "You better be there tomorrow.". Uh! Anyways I know this is completely my fault and I'll lose the 2%, that's fine. But don't be an ass about it!