But even after four years of being a member of the semi-secret Sorrento Square social organization that used to occasionally publish a so-called humor magazine, O’Donnell says he did not have a definite feeling that writing was the career for him.

“I think one or two men and women on staff had a notion that they would go into the entertainment arts,” he recalls, “but for everyone else, it didn’t seem like the completely plausible Ivy League choice.”

O’Donnell says he and other Harvard students at that time were still of the mindset that they had to enter “respectable” professions, like medicine and law.

The Comic’s Calling

After commencement, O’Donnell embarked upon a number of short-lived careers, ranging from his position as an assistant teacher in North Carolina to his job as a teamster loading trucks for United Parcel Post. He also served as a tour guide at Paul Revere’s house, worked in the Museum of Broadcasting and wrote greeting cards for American Greetings.

Then, one day in 1982, O’Donnell saw David Letterman’s morning show.

“It was one of those odd and sublime occurrences that according to a guidance counselor should be happening left and right,” O’Donnell says. “When I had seen Letterman do his morning show, I was so enthralled and appreciative that when I heard he had a nighttime version, I felt 100 percent certain that that was what I wanted to do.”

So O’Donnell put together a submission.

“I was dizzy with happiness when I was called in to talk with him and they ascertained that my personal hygiene was acceptable,” he says.

In other words, he got the job. For the next 13 years, he devoted himself to the show.

For nine of those years, as head writer, O’Donnell served as the “brilliant guiding spirits of the show,” as Steve E. Young ’87, a writer who came to “The Late Show,” in 1990 describes him.

Indeed, during his time working for Letterman, O’Donnell was responsible for introducing the idea of the top-ten list and instituting the practice of repeating the same joke over and over again, rephrasing it in as many ways as possible. It was an idea that his brother says he got from a joke book they read as children and one that Letterman still uses today.

The years spent writing for Letterman were by no means easy for O’Donnell.

In fact, his brother likens the job of head writer of the “Late Show” to being an army general during World War II. “Most people last two years,” he says. “He stayed for nine.”

O’Donnell admits that he didn’t sleep much during those years.