You Mean That I Don't Look Like an Economics Major to You?

I sailed into my writing class, took a seat in the front row, and turned around to speak to Adam.
"You're not in this class--are you?"
"I think so," I said, "this is--"
"This is Economics: Blah blah blah."
I thanked Adam for saving me from being one of those kids who get up to leave a class after the teacher introduces it and left the room to find the one I needed. Apparently, rooms 502 and 520 aren't the same.