A pessimist sees a dark tunnel.

An optimist sees light at the end of the tunnel.

A realist sees a freight train.

The train conductor sees three idiots standing on the tracks.

Pollen: When flowers can't keep it in their plants.

Oh, and in reply to the poem illustrating the ridiculousness of the English language:

English isn't a language. It's three languages stacked on top of each other wearing a trenchcoat.

One more because I feel like I'm not the only one in this forum who can relate to this:

Remember "TAXI" ? Christopher LLoyd's

"I DON'T KNOW WHAT'S RIGHT. I DON'T WHAT'S WRONG. I DON'T KNOW WHAT'S GOING ON." 

It's the right comment in so many area's. I also had a saying used a lot. I can only remember the punch line. 

...............WHEN YOU FEEL DOWN AND OUT LIFT UP YOUR HEAD AND SHOUT "OH SHIT!"    Friends will help the crowed will get out of the way.

Laugh everyone it is good for you. TOAD/Otter/MOUSE

When my nephew started first grade, he came home and told his Mom he did not need to go back to school.  She asked him why? He said well, they're teaching colors, numbers and reading and I know how to do all of that. 

Not really a joke, but you might get a chuckle out this.