Ok, I have a dumb one for ya then.
So there's this guy, he's going out for his morning jog, and after a few minutes, he hears a voice coming from a few blocks away. As he got closer, he realized it was the voice of an elderly man, and he was screaming "Twenty three! Twenty three!" over and over again. The man decided to investigate, so when he turned the corner, sure enough, there was an old man, jumping up and down on a manhole yelling "Twenty three! Twenty three!" The man was dumbfounded, so he asked "What're you doing that for?!"
The old man stopped jumping for a second, and said "What, this? Well, you see, when you jump on this manhole and yell "twenty three", you're somehow able to jump really, really high, but you've really got to put a lot of effort into it.
The man looked incredulously at him. "Oh come on, like I'd believe that!"
The old man glared at him. "Hah, try it for your self and see!"
The man didn't believe a word of it, but he figured there was no harm in trying. The old man moved aside and the man moved into his place and started jumping. "Twenty three. Twenty three." He said without any effort.
"No, no, no! You're doing it all wrong!" Said the old man. "You've gotta put all yopur effort into it!"
"Twenty three! Twenty three!" The man yelled, hardly getting off the ground.
"No, more! More effort! Jump as hard as you can and scream at the top of your lungs.
Annoyed, the man complied, putting everything he had into his jump, he bellowed "TWENTY THREE!!! TWENTY THREE!!!"
"Yes that's it! Wow, you're jumping even higher than I did!"
Surprised, the man kept it up. "TWENTY THREE!!! TWENTY THREE!!!"
And on his last jump, the old man moved in, and yanked the lid off of the man hole as the younger, most notably dumber man fell into the filthy sewer below. Looking somewhat satisfied, the old man replaced the lid and moved back onto the manhole. Looking about to make sure everything was clear, he began jumping once again. "Twenty four! Twenty four!"
Yeah well, lame, but worth a chuckle ;P