This post contains spoilers for the entire series of Adventure Time, including the Season 9 finale

Adventure Time redefined what it meant to go on a journey.

The finale of the 10-year-long adventure, which aired at 6 p.m. ET on Sept. 3, could not have made that more clear: We have moved so far beyond where we started. We could never have imagined the twists along the path. We can't believe it's over. But somewhere along the way, we learned to be OK with seeing it go.

The finale reiterated that good things might need to come to an end. But what we learn from them doesn't have to.

In its more simple (yet always revolutionary) original form, creator Pendleton Ward imagined Adventure Time as an animated TV series in the spirit of a Dungeons & Dragons game. The sense of random, unpredictable questing is built into the name itself.

But what was perhaps more unforeseeable was what it came to mean to us, as an endless source of heartfelt journeys.

An unexpected moral compass, Adventure Time is the closest equivalent the internet era has to what Mr. Rogers meant for so many previous generations. Through its oddities, rituals, sincerity, and never-too-soap-boxy lessons, it taught us the invaluable lessons of growing up — both for the show's younger audiences and the older online fanbase that took to it like moths to a meme.

The Land of Ooo is not the same as Mr. Rogers' neighborhood. But it was still our place of unadulterated childhood imagination and community, where the scary and beautiful lived side by side, the achingly sad and unrelentingly hopeful sang in harmony together.

We watched so much about the world change. Adventure Time dared to go places that few other children's shows were even allowed to.

Our own place of unadulterated childhood imagination and community, where the scary and beautiful lived side by side.

As a universe set in aftermath of total annihilation (aka the nuclear fallout of the Mushrooms Wars), the show has always in some ways been about living with the end. But the ephemeral nature of life is also embedded into its most notable storylines.

Like the Ice King, for example. A character we assumed to be a prototypical villain turns out to have been a scientist, loving husband, and caretaker to a little girl in need — but then tragically corrupted by the magic he needed to protect them in the post-apocalypse. The princess who needed saving now more often does the rescuing herself. She's also revealed, however indirectly, to be in an on-and-off again romance with Marceline the Vampire Queen.

A seemingly simplistic protagonist goes through the awkward and excruciating pain of losing love and wrestling with the discovery that the dad he'd put on a pedestal was actually just a huge jerk.

The "Adventure Time" finale take place in a backdrop of war and destruction Image: Cartoon network

Finn began as a falsetto-ed boy with reductive ideals of violent heroism. But by the end of the series in Season 9's "Gumbaldia" and "Come Along With Me," he has transformed into a peace treaty-seeking mediator. In the finale, his immutable shadow self Fern the Human disintegrates and is reborn as the new treehouse. Betty merges with the horrifying chaos god Golb.

I mean, for Glob's sake, we thought Tree Trunks literally died for much of the earlier seasons.

Adventure Time has been preparing us for how to say goodbye for a long time now. And it pushed those lessons even more in the ambitious, hour-long finale. From the opening minutes, the audience is further forced face the end as just the natural process of change.

Because the episode begins not with Finn and Jake, as we've come to expect. Instead, its end begins with a whole new duo, Shermy and Beth, who look like some sort of mutated futuristic evolutions of Finn and Jake.

The plot of the finale is even framed as a story being told by the king of Ooo, BMO, looking back a thousand years after everything we knew and love has been gone forever.

Adventure Time knows that life is not always fair or just. Everything stays, yet always changes. Bad things happen to good people. Good things don't last forever. And that's exactly as it should be.

Or, to put it in the words of the finale song, written by one of the formative creative minds behind the show (who went on to spread its revolutionary spirit with Steven Universe), Rebecca Sugar:

It seems unforgiving when a good thing ends.

But you and I will always be back then.

...

That's why

You and I will always be best friends

Saying goodbye to Aventure Time is hard, especially when it feels like we need a show that can find peace amid the chaos now more than ever.

But it's a testament to what it gave us that we've learned how to let go. We came along with you. We'll be here for you always. And always be for you.