Ok ok... they do have a sense of humor but... age related cognitive decline has led to many older adults not getting 'the joke'. In a study by Wingyun Mak and Brian Carpenter, Ph.D. , of Washington University they discovered that

Humor comprehension in older adults functions in a different fashion than humor comprehension in younger adults. The researchers studied older adults from a university subject pool as well as undergraduate students. The subjects participated in tests that indicated their ability to complete jokes accurately as well as tests that indicated their cognitive capabilities in areas of abstract reasoning, short - term memory, and cognitive flexibility. Overall, older adults demonstrated lower performance on both tests of cognitive ability as well as tests of humor comprehension than did younger adults.

Interested? Here's the rest of the press release and the citation:
Journal of the International Neuropsychological Society (2007), 13: 606-614

Posted to the Omni Brain Facebook group (thanks David!):

This is bizarre! How smart is your right foot? Just try this. It is from an [unidentified] orthopedic surgeon [in an email meme].

This will boggle your mind and you will keep trying over and over again to see if you can outsmart your foot, but you can't. It's preprogrammed in your brain! [ZOMG!]

1. WITHOUT anyone watching you (they will think you are GOOFY) and while sitting where you are at your desk in front of your computer, lift your right foot off the floor and make clockwise circles.
2. Now, while doing that, draw the number "6" in the air with your right hand.

Your foot will change direction.

I told you so!!! And there's nothing you can do about it!

Can anyone explain the mechanism behind this?