You don't have to think really hard to get the joke. I think humor in general appeals to all people.

Do not spit gum in the drinking fountains.

Dogs do not grasp the concept of house cleaning.

I really try to think cinematically, because that's how people read. They create a theater in their minds.

I've come to realize that you're going to get criticized no matter what. Somebody will always hate what you write, especially if you write humor for a fairly broad audience. Somebody will always find it not funny and declare you're not funny anymore. And sometimes people are just crazy.

We don't shoot somebody soon, I'm gonna forget how

Here's a simple experiment that you might want to try if there is absolutely nothing else going on in your life. All you need is a cork, a bar magnet, and a pail of water. Simply attach your magnet to your cork, then drop it into the water, and voilà (literally, "you have a compass")-you have a compass. How does it work? Simple. Notice that, no matter which way you turn the bucket, the cork always floats on top of the water (unless the magnet is too heavy). Using this scientific principle, early hardy mariners were able to tell at a glance whether they were sinking!