Finn probably met a human, Susan Strong, but this is unknown. But there is one human the creators are planning for him to meet, Fionna. They probably won't meet, since there has to be a huge gap between the two (Looong Theory) but as probably self explained, the fun thing about is Fionna is the opposite gender, along with other of her friends, matching the characters in the main show. Du can see the theory in the Frage "is there any other humans beside Finn."
Maybe but He has an amazing world! unlike our world (Our world will not turn without money and wars for places like countries being taken Von other countries) I like his world and being the only human makes him Original!
