Alright. I've been doing some reading, and the most popular theory is that Adventure Time is set in a post-apocalyptic Earth, with all humans either being mutated or killed off due to the detonation of the Mushroom Bomb. Well, scratch that. If you haven't seen "The Vault" it's the episode where Shoko appears, and we learn about her backstory. So we know that Shoko was around after the Mushroom War. Okay, what does that mean? Well, it actually means a lot. If Shoko was around after the bombing, born as a humanoid, then how can Finn be her incarnation? Humans were extinct, yet Finn was born supposedly as a 100% human. Impossible. How does this fit in with the theory that Adventure Time is post-apocalypse? It doesn't. It fits with the second most popular theory. That Finn is in a coma. All of the things that Pendelton Ward thought we couldn't figure out, we did. And that proves that a pre-teen is dreaming up the Land of Ooo, and that Finn is in a coma. The apocalypse never really happened in Adventure Time, it was simply dreamed up by a boy with a wild imagination, and who went through something awful. Also, some of the "mutated" humans cannot possibly ever truly be a mutation. I'm talking about Prismo. You all know him, if you're smart you hate him. Prismo is a being of an undetermined rank and an unknown type of life form. Is he even a life form, or just a spiritual being? Prismo is rarely even in the show, but as with Shoko, the most important characters are often the lamest. Prismo cannot possibly be a mutatation, as he is best classified as a being of pure energy with no weakness. (Yes that was a Gravity Falls reference.) Because of these small, but key pieces of evidence, it leads me to believe that this is the most plausible theory of Adventure Time. That Finn is in a coma. Don't kill me for adding this, but Finn could also be dreaming, and is simply asleep. Both of those theories fit this evidence. Okie-dokie-lokie, thanks for putting up with me for this long, bye!
~Rainbow Dash
So I did some more digging and found out some info about our favorite cartoon. Finn is not in a coma. He is not dreaming. The Mushroom War is not a real event, simply something Princess Bonnibel Bubblegum came up with to explain the crater in the Earth. Princess Bubblegum was the first mutation, a scientist accidentally mutating herself during an experiment. She mutated humans so she would not be alone, and decided to create the Candy Kingdom. She almost mutated Finn, but she couldn't. (What she did with Finn is similar to what she did to Flame Princess, that's why she refuses to start a romantic releshinship with him.) So, I personally don't believe this theory. We were discussing it at our most recent Awesome Animation Cartoon Club meeting. My friend, Lumpy Space Princess (We all take names from our favorite cartoon characters. I'm Rainbow Dash from My Little Pony.) came up with this theory herself. She thinks that Princess Bubblegum is 1,000,000% evil! and spends her time at our meetings trying to prove it to us. So, if you believe her theory, comment to let me know and I'll tell my friend that you agree with her.
~Rainbow Dash
Oh my glob!!! Thank you Hypnosifl, because of your constructive critism, I just realized something. If Prismo is just the dream of an old man, the old man looks human, that old man is African-American, and we know another old man who fits all of those criteria, I think that Mo is dreaming of Prismo, and that is the premise of adventure time. It would make a little sense, but then again there definitely are flaws in that theory. The old man seems to be in a different setting than the Mo Factory, and he's not hooked up to any machines. He also has a beard, but Mo does not. The more I think about this, the more I realize it makes no sense. Sorry!
~Rainbow Dash