Three Seasons Only

''"There's spring, summer, and fall. I disown winter!" Not that kind of seasons.''

When the first few seasons of a show being considered good by its audience and critics while later ones are, at most, moderate. This is a sign that a TV show or series is in the process of losing its magic if it didn't lose that magic already. It may still have some of its former glory lingering in the episodes, but the episodes are still mostly Too Boring To Survive. If the creator is smart enough, they'll go with the difficult-yet-dignified option of Canceling The Whole Thing instead of being around for much longer than anyone is willing for them to.

There Are Only Three Seasons got its name from SpongeBob SquarePants and how audiences and critics felt that only the first three seasons were worth watching, being the most memorable and quotable of the show in their opinion, while later seasons lacked the magic the first three had.