"Happy Days," one of the best TV comedies set outside New York and Los Angeles, gave us classic catchphrases, the legendary “Jump the Shark” trope, and quite possibly the greatest theme song in the medium's history. Over the years, the show also introduced us to unforgettable characters like the Fonz, Richie Cunningham, and Mr. C, as well as several others who would go on to have their own spinoffs. However, the show also introduced another phenomenon folks call “Chuck Cunningham Syndrome,” which has since reared its head countless times on some of the most popular sitcoms known to man.

But what is it, why’s it a thing, and why have some of us thought about it nonstop since watching a random Nick at Nite commercial more than a quarter-century ago? We might not be able to answer the final question, but the other two won’t be a problem at all…