"Calculus: It's Like An Ambigram."

Calculus I, in a nutshell:

Prof.: "Here's how to do derivatives."
Class: "Meh."
Prof.: "Lost yet?"
Class: "Completely."
Prof.: "We're going to be doing this for the rest of the semester."
Class: *Groans*
SOME TIME LATER...
Prof.: "We're almost done with the semester."
Class: "Yay!"
Prof.: "So now we're going to do everything BACKWARDS!"
Class: "Wait, what?"
Prof.: "So forget everything you just learned, because we've got just three weeks to do the exact opposite of what you've been learning for months!"
Class: . . . What?
Prof.: "It's called integration, and it's the most important thing you'll learn. Should be easy, right?"
Class: *Minds implode*

Fun fun, eh?
Well, back to studying.