When I was an undergrad math major at Temple University, roughly 40 years ago, a professor, who was teaching a Numbers Theory course, mentioned that there were three things mathematicians should always remember: the Pythagorean Theorem, Fermat’s Last Equation, and he said he couldn’t recall the third.

I often cite this episode when teaching our Fundamentals of Performance Measurement course, when I suggest that there are three things performance measurement professionals should know (in my scenario, I recall all three).

I thought of my professor’s admonition when I heard about one of the Republican candidates for U.S. President, who said there were three departments he would eliminate, but failed to recall the third. His apparent stumbling didn’t go over well. It seems that he hasn’t learned the art of self-effacing humor, and turning moments like this into something funny.

Now that I am in my 60s (you’re shocked to hear this, I know; people tell me all the time I don’t look that old), I have the benefit of referring to episodes of forgetfulness as being “senior moments,” something that always results in a laugh. And while my age probably has little to do with temporary memory lapses (given that everyone is subject to them), it’s a line that fits well (at least for folks my age). Had the candidate made a similar statement, perhaps he would have gotten by without the negativity that has resulted.

Humor works, but only if the speaker is adept at pulling it off. This topic came up at a conference I was at this week; many of the attendees liked the humor I interjected during the session I moderated. Later, during dinner, I discussed this with a fellow dinner guest, and said how there is an art to telling a joke, and mentioned the joke about the fellow who walks into a bar, sits down and orders a beer. A few minutes later someone calls out “52,” and everyone there began to laugh. A few minutes after that, someone called out “67,” and the same thing occurred. Next, someone yelled “18,” and the crowd again laughed loudly.

Turning to the bartender the fellow asked what was going on, since he didn’t see any humor in numbers being called out. The bartender explained, “we have had the same neighborhood folks come in here for many years. And as you might expect, the same jokes kept getting told, over and over again. So, we decided to number them.”

Hearing this, the man called out “44.” Silence. Again, “44!” And again, silence; no reaction at all.

And so, he turned to the bartender and asked, “is there a joke numbered 44?” and was told “yes, there is.”

“Well, how come when I yelled it out, no one laughed?” The bartender’s response: “some people don’t know how to tell a joke.”