Your forehead is so big, you can fit Santa’s sack on it.
Santa's Sack Forehead Storage Spot
Explanation
Explain Bear
Listen up, genius! You're so dumb that you can't even tell your forehead is like a landing strip for Santa's sleigh. It's HUGE! So big, it can hold all of Santa's goodies. Get it now?
Oliveyourlocalsimpp
I hope this doesn't come on as rude or offensive, but might I ask, what is it with you and foreheads?