Smart jokes?

Smart jokes?  Friend and reader Simon M. passes along these “20 Jokes That Only Intellectuals Will Understand”.  That's more than a little pretentious, but there are some funny ones in the collection.  One oldie-but-goodie that's geek-friendly:

Why do engineers confuse Halloween and Christmas?
Because Oct 31 = Dec 25.

Translation: 31 base 8 (OCTal) equals 25 base 10 (DECimal).
Here's one I hadn't seen before:

Entropy isn't what it used to be.

Ha!