What fallacy is this? Me: "Why do elephants paint their toenails red?" You: "Why?"

This question strikes me as (1) frivolous or trite; or (2) an infantilization of this forum.  There are myriad real-world examples of fallacies broadcast daily in the MSM, which are worthy of deconstructing: this cartoonish submission, simply an absurd exercise.  

How about if it's rephrased:

Crystals prevent  cancer.

I've worn crystals for years and I've never developed cancer.

Another TOO common real world example of this:

If Trump was chosen by God, he would be a flawed person (like other flawed people in the Bible that God chose to do his bidding).

Trump is certainly a flawed person.

Therefore, this is evidence that Trump was chosen by God.

Piffle.

We're all flawed, not just Trump.

Piling on?

We're all flawed, not just Trump. 

Theologically, all humans are flawed, so having to say "God chooses flawed people" makes just as much sense as "God chooses human people." You are using Equivocation here. In the context of the argument, "flawed" is not "non-perfection;" it is more like "morally deficient."

Well, gee, it was your use of "flawed" that I relied upon for accepting your premise.  If you meant Trump, in the context of the argument, was "morally deficient" it was your equivocation, not mine, when you said "flawed" instead of "morally deficient".

I know my question was just plain silly. I'm pretty new here, and I didn't realize that humor is considered inappropriate in this forum.  How about this: "Why do you take aspirin every day?"  "Because I get a lot of headaches."  "Have you ever gone a day without taking aspirin?"  "I did once, and I got a headache.  That proves it works."

As Bo said, clearly this is a joke. However, thanks for your post. Some people make statements that sound just like this, that should be jokes, but are not. So, there is still something to learn about fallacy from the Bo's answer, and perhaps others that may follow. :D