One of the biggest things about Adventure Time is that as seasons progress the series gets more mature. The show goes from a young brilliance to gradually mellowing out without losing its base identity. Because it grows up along with its audience.
Growing up means realizing that sometimes you will come across emotional roadblocks. I mean, good god, just think of the trend of characters’ rocky relationships with their fathers.
Sometimes during those roadblocks you realize that a simply sorry can’t fix everything. If you change for the better it doesn’t necessarily obligate anyone to take you back (Re: Finn with Phoebe). And sometimes the more you push the more you make the other person distant.
Hurting sucks, but it’s better if you have a shoulder to lean on. If you want to learn to love again you need to be honest with yourself and others. (Princess Bubblegum and Marceline.) You can’t always look to objects for abject emotional stability. You need people. People need you. (Princess Bubblegum again)
But god, one of its most poignant parts is that its morals and characters don’t get always solved instantly... or even at all.
In a world of magic solutions and intentions aren’t.