if it was 15 years before Finn was born, Were there humans would there be like a civilization of humans, and when Finn was abandon were did his parents go

dead... または alive searching for him.... see あなた can never predict AT because of all the awesomeness!!

I don't have an exact answer for all of your 質問 but here are some rumors that I heard that might help.

1. Susan Strong might be Finn's mom,It's not known for sure what happened to Finn's dad. Possibly dead.

2. (This one is far fetched) Before Simon/Ice King アナと雪の女王 the world Finn was placed in a cabbage because, they resist radioactivity. Then after the Ice Age he unfroze in front of Margret. Whom then adopted Finn.

3. There is a secret tribe/community of regular people.