Over the past 30 years, certain comedians have made themselves known as outstanding guests on late-night talk shows. From the established legends like Steve Martin and Martin Short to younger comics like Nikki Glaser, the spot on the couch next to a host has become a place for some of the greatest comedians to become favorites.

In that time, however, nobody funny has been funny on late night television in quite the way that Norm MacDonald has been, which is part of why the comedy world was devastated by his unexpected death at the age of 61 last week after a private nine-year battle with cancer. 

In the last week, his classic talk show appearances, specifically those he made on the programs of Conan O’Brien, have been passed around on YouTube more than they had ever been before. A few things about Norm have become abundantly clear to the general public in this time, chief among them being that the man was a comedic genius on a completely different plane than anyone else.

MacDonald had a tendency to sit down in the chair next to a host like O’Brien and tell old, corny jokes. Oftentimes the jokes that he would tell would not even be his. What would make his appearances so clearly works of strange brilliance were the roads he would take to get to his typically pun-filled and hackneyed punchlines. Norm would extend what were originally 20-second jokes into 5-minute grandpa stories, flavored by his own signature mastery of the English language. It made for incredible television every single time.

The best example of this incredible skill that Macdonald had was his now infamous “Moth Joke,” performed in 2010 during Conan’s short-lived stint as the host of The Tonight Show. In its most basic form, the joke is quite simple: a moth goes into a podiatrist’s office, and he begins to tell the doctor about all of the problems in his life. When the podiatrist points out that the moth’s issues would be better addressed by a psychiatrist and asks the moth why he came to him, the moth responds that the light was on.

That joke alone is certainly not enough on its own to make its teller into a comedy genius. In fact, MacDonald later said that his friend and fellow comedian Colin Quinn was the one who had originally told him the joke years earlier. What made Norm’s telling of the joke such an eloquent display of his delightful madness and such an incredible flex of comedic muscles was the fact that he turned the quick joke into a four-minute piece of comedy. 

For many comedians, taking up so much time for such a quick joke is a recipe for a career disaster. For Norm, it was just one of many comedic risks he willingly took in his career.

The way that MacDonald was able to fill up so much time was by taking the idea that the moth was having troubles in his personal life and extrapolating it to an unheard of level of absolute madness. The moth essentially became a character in a tragic Russian play, reminiscent of the works of famed playwright Anton Chekhov.

MacDonald had often said before that one of the greatest influences on his work and career was the Russian novelist Leo Tolstoy, best known for his elongated masterpiece War and Peace. That ability to use the English language to extend a sentence to its furthest possible capacity, plus a clear knack for the typical names and plotlines found in Russian tragedies, is what allowed Norm to make a joke about a moth into what is perhaps the most memorable moment of his odd but glorious career.

The moth feels lost and trapped in his job, has fallen out of love with his wife, lost his daughter in the cold of winter and begins to feel the same hatred for his son that he feels for himself. It’s ludicrous. It’s downright unreasonable. It’s absolutely hilarious.

The best part of the joke is the revelation since Norm’s death last week that the joke only happened because MacDonald was asked to be on an extra segment on Conan’s show that night and had nothing prepared for it. The joke was a spur of the moment attempt by Norm to extend a very quick, very corny joke into a full segment, and what he ended up doing was giving us a tour of the way his brain works.

Norm MacDonald’s brain was clearly a unique and special phenomenon in the world of comedy, and the Moth Joke is a perfect example of what made such a brilliant comedian and an entertaining talk show guest.