Why bad jokes are easier to remember than the good ones

Scientists have explained why the best jokes are the hardest to remember, while the worst are easily called to mind.
http://www.telegraph.co.uk/news/newstopics/howaboutthat/5032755/Why-bad-jokes-are-easier-to-remember-than-the-good-ones.html

What do you call cheese that belongs to someone else?
Nacho cheese.

Bad-a-boom! I'm here all week, folks --try the veal.