Blathers is one of few characters that has an extensive history in the games. He grew up in the city, living with his parents, until he finished school and went off to university. It was here that he earned many degrees and was going for his doctorate, until one of the professors mentioned to him about taking a position in the country museum.
He was excited to take the position and still has it to this day. Because of this, though, he did not finish his doctorate, although he knows many things on the items that are donated to the museum. It wasn't until Animal Crossing: Wild World that Blathers could identify fossils, instead of having them sent away to be identified.