It is a pun based in the popular mid-1990s TV ads for D.A.R.E. The normal ad was just film of an egg being fried in a frying pan. First, the egg was cracked and dropped into frying pan, along with commentary saying, "This is your brain...". Then, the camera skips forward to the egg being fried, and the commentary goes, "This is your brain on drugs. Any questions." Google that and you will find the original commercial.