There's a time and a place for head-banging... The shower isn't one of them. Maybe now you'll learn not to be a fool.

I don’t care what you were doing, nobody deserves a concussion. Don’t rush the healing. Long term effects can be devastating if you don’t take care of yourself. But, at least you got a story. Most concussion stories are funny.

Singing in the « rain » is very dangerous...

Headbanging is written together. Otherwise it means something else.

At least since it was in the shower you can lie and say you just slipped

Were you taken to the hospital naked?

if there was some heavy music, then rock on. if not... then this is just weird. on the upside, rock and roll will never die, so you should be alright.