One of my favorite jokes and, less importantly, why

A couple of years ago, an Oxford University study determined (don't ask me how) the 10 funniest jokes ever.

You can peruse the list for yourself. Inevitably, you'll chuckle at some and scratch your head at others. Not because you don't understand them, but because you'll be thinking, "Wait, THAT'S one of the 10 funniest jokes ever?"

Because humor is, as much as anything I can think of, a subjective endeavor. I know this because my wife and I often have what is commonly termed Incredibly Opposite Senses of Humor. Something will bring me to tears I laugh so hard, and she will look at me without the trace of a smile and shake her head, as she often does as she wistfully looks back on the day of our marriage and wonders how things could have gone so horribly wrong.

The point is, one man's gut-buster is another man's "Huh?"

My absolute favorite joke from that scientifically proven list of 10 is this one:

A guy is sitting at home when he hears a knock at the door. He opens the door and sees a snail on the porch. He picks up the snail and throws it as far as he can. Three years later there's a knock on the door. He opens it and sees the same snail. The snail says, "What the hell was that all about?"

I first heard that joke, or some variation of it at least, many years ago. But it still makes me laugh even today. Why? Three reasons:

(1) The Unanswered Questions: Why was this snail coming to the guy's door? Why did the guy react by throwing the snail away? Did he realize the snail could talk, or no? What is so important that the snail spent three years of his life slithering back to the front door so he could get another chance to talk to the guy AND voice his displeasure? I love thinking about all of these things.

(2) The Swearing: Yes, I consider "what the hell" to be "swearing." This is because, as a general rule, I don't swear. I never really have much. Don't know why, just didn't. So it still has a bit of a scandalous comic effect on me when I hear it. And I love the idea of the indignant snail saying it.

(3) The Absurdity of It All: You either like Monty Python or you don't. There's no in between. Same with a hundred other comedians, actors, sketch groups, etc. I love, love, love Python, whose skits and movies always rested on some comically unreal premise. The whole situation with the snail having a valid reason to visit this guy's house is hilarious, even apart from the joke itself.

I may have over-analyzed that a little, but if nothing else, it gives you a sense of what makes this 47-year-old white American male laugh. It's a tad frightening, I know.