Spongebob, America’s favorite absorbent, yellow, porous protagonist, can vote. It has been 18 years since the only speaking member of the phylum Porifera and his hometown of Bikini Bottom first debuted on Nickelodeon. During that time, Spongebob has become something rare, a prominent pop culture figure derived from children’s entertainment. Think of children’s characters that have thrived in the mainstream like Spongebob: There’s Bugs Bunny and Kermit the Frog, sure, but the list after that is pretty much just friends of Bugs Bunny and Kermit the Frog. Children’s cartoons don’t tend to last and they definitely don’t last for 18 years. So how did Spongebob Squarepants defy the odds to become The Simpsons of kid’s TV? By having the courage of its absolutely bizarre, totally childish convictions.

A year in a kid’s life can mean entirely new interests, meaning that what was once the funniest show in the world can suddenly be the dorkiest thing in the world. For this reason, kid’s shows, even popular ones, tend to only last a couple seasons at most. Shows like Lizzie McGuire, The Last Airbender, and Duck Tales had massive ratings and were massively popular, but none of them made it past their third season. To say that a kid show was pulled off the air is merely to observe a fact. It’s not a value judgment. There are plenty of good shows that disappear.

Spongebob hasn’t survived because it’s good (though it is). It also hasn’t survived because it appeals to adults (though it does). If that were enough, wouldn’t Gravity Falls still be on? The reality is that Spongebob’s success can only be understood in terms of Spongebob. Sometimes the thing is the thing. So it is with The Simpsons and so it is Spongebob.

Weirdly, Spongebob’s longevity is likely less a result of creator Stephen Hillenburg’s creativity and more a product of his staff’s commitment to making essentially the same show again and again. Flexible as he may be, Spongebob is a remarkably consistent character in a remarkably consistent world. Spongebob has never matured. This is key.

It doesn’t matter if Spongebob is battling Neptune or trying to catch a jellyfish with Patrick, the show never loses focus of the defining feature of Spongebob: childish wonder. This child-like spirit is best shown in “The Idiot Box”, where Spongebob has the time of his life simply playing pretend in a cardboard box. That’s it. That’s the show. Spongebob is always amused and astounded. Every other feeling he has seems to be fleeting. Spongebob does not have a rich internal life and does not learn lessons about himself over the course of long narrative arcs. He’s a Sponge. He takes the world in.

The show pipes in tension and contrast using other characters, most of whom seem adult and broken. There’s Spongebob’s boating instructor Mrs. Puff, who is completely devoid of any joy or hope in her life and loathes everyone around her. There’s Spongebob’s boss Mr. Krabs, a creature driven so mad by greed he gambles with his employees’ lives. And there’s Plankton, the owner of the Chum Bucket who dedicates his entire life to gaining power and respect by stealing the Krusty Krab secret formula.

Spongebob is not optimistic about mankind or seacreaturekind. It’s optimistic about Spongebob.

This is why Squidward, Spongebob’s cantankerous next door neighbor, is the key to understanding the show. Squidward is the antithesis of everything Spongebob represents. He is a sad, angry, and bitter squid and he goes out of his way to make others wallow in their own misery. When Squidward, Patrick, and Spongebob find themselves stranded in the wilderness for the foreseeable future in “Club Spongebob”, Squidward lashes out at Patrick and Spongebob for having the audacity to believe that things are going to be okay. And does the show reward Squidward for his skepticism? Nope, instead, he is left to starve as his two idiot friends enjoy a feast that literally fell right out of the sky. There is nothing either good or bad, but thinking makes it so.

The question this presents is whether or not Squidward’s cynicism drives his misfortune or is a product of it. The show seems to vacillate on this point. At times, Spongebob is about a happy childlike character putting out good and getting good back. Other times it’s about an idiot failing up. The speed with which it vacillates between these two modes lends it emotional depth without sacrificing the purity of childrens’ viewing experience. Kids don’t sympathize with Squidward.

And that’s not going to change. Squidward isn’t going to lighten up. Mr. Krabs will continue to exploit the people he loves. Plankton will never find peace with what he has. Mrs. Puff will continue to be consumed by rage each time Spongebob finds a new way to crash a boat. And Spongebob will be happy because his happiness is internal. After so many years, the show provides that comfort to adults in the know and that tonality to kids on the couch. Childishness ceases to be a weakness if you stick with it. It becomes the art of war.

Where does Spongebob go from here? At this point, he and his eponymous show don’t really need to go anywhere. As long as Spongebob is a happy, naive spongechild who effortlessly cruises through life while his jaded, bitter contemporaries struggle, Spongebob will continue to be eminently watchable to both kids and adults. Unless the people making it get bored, there’s no reason to think it’s going away. In an era of shaky institutions, you can count on Spongebob.