I just thought of another one, more personal to me but would have been useful nonetheless.
"Brogan, I KNOW your drama teacher's name is Stu, but when you have the witty idea to make his name into a pun and start referring to him as Dumpling, do NOT say it to his face. He WILL tell you to ****** off, and WILL loathe you for the entire course."
If only I'd been warned. Perhaps then I wouldn't have spent so much time hiding in the lighting box after being yelled at, "DON'T CALL ME DUMPLING!"
Still, the memories are worth it :')