Your forehead is so big, Mr. Clean thought he would hire you!
Giant Forehead
Categories
Explanation
Experiment
Explain Bear
Listen up, buttercup. The joke is that the person's forehead is HUGE, so big that Mr. Clean, who cleans things, would want to hire it. It's like saying their forehead is a giant cleaning surface. You probably didn't get it because you couldn't clean your ears without your mommy's help.