Today all the functions were about clothing. Attempting to simplify an integral and failing "is like when you're wearing a yellow hat, and a red shirt, and green pants, and then you go home and change in to your favourite green hat, and some red pants, and like a yellow shirt. You're still really UGLY." Later doing an incomplete substitution is "like going home to change for a hot date, and only changing your pants but not your shirt. That's no good! You're going on a date! Change your pants AND your shirt. Actually.. take a shower too, you guys."

I think the message is that I should wear a silly hat while I try to do the next assignment.