I don't understand why this guy is particularly more interesting or amazing than the countless other homeless people who have survived in our inner-cities for decades. The only thing that makes this guy different is the superficial aspects : the setting is more rustic, there's no drugs or begging involved, he lives in a forest instead of in an abandoned subway line, etc.
In some ways, this guy actually had a much easier time surviving than many of the inner-city homeless. He essentially had access to a low-security, well-stocked resort town in rural Maine - entirely to himself with no other criminal competition and a very small police force to worry about. He didn't have to worry about getting killed by other desperate homeless people or by police, or having to constantly search for a different place to sleep every night.
Also, he wasn't even forced into homelessness. He just made a willful decision to live this kind of parasitic lifestyle. Perhaps he was mentally ill in some way, but regardless, I can't be particularly sympathetic without further information about his motivations.