It occurs to me that 30 year old Marco was never an adult to begin with as he never had to deal with the realities and responsibilities of growing up on earth when chasing Heckapoo for 16 years. You can see it with his reaction to seeing Star, thoughts?

Long post, consider this the final product of three days spent thinking about this episode.

Oh yeah, I agree. There are several reasons to believe that this is what the writers were going for. While in Hekapoo’s dimension Marco didn’t really grow to become an adult, he was just a teen in a 30 years old body. Having spent all that time focused on his quest, in a “fake life” away from home, his loved ones, and responsabilities, he basically created himself the “bad boy” image he craved so much. Something that he didn’t actually need anymore, at least on Earth, after having met Star and all the new friends she brought.



As an “adult” he still tries to act cool

He still has “a bike”

as soon as he sees Star, he drops the “cool macho man” talk, and is back to being an excited teen who can’t wait to tell his friends all the cool experiences he had during… a vacation abroad, something like that.

This line here is against everything the show, and Marco, stand for: a life of freedom, with no responsability whatsoever. This is the little kid in Marco who says “I’m an adult now! I can go to bed late and eat cake everyday!”. That’s obviously not who Marco is.

And he realizes it as soon as “real life” catches up, as soon as Star gets there. It’s not just “I can’t leave my loved ones”, it’s also “What the heck was I thinking.”

Adam’s tweets about this, while not necessarily canon, support the idea: those 16 years felt like a breeze to Marco, who didn’t even stop to think about the mistake he was doing.

While in Hekapoo’s dimension Marco acquired new skills that might come into play later in the show, but he didn’t really mature.

Marco didn’t mature during those 16 years, he matured as soon as he was back home, and he realized how important what he has is, even having to walk the puppies under the rain.

Having to go through the pains and insecurities of puberty is worth it, when he is among people he loves and who love him.