After leaving Monstropolis at the ripe age of 11, after your mother could no longer afford to raise you, let alone keep herself alive, you went to your father's in the small town of Mawgutt. You tried to keep in touch with your mother and friends from Monstropolis. All fell through and eventually your mother stopped even trying to reach out. Except for one small green monster, he really was the only one to put in the time and effort to keep in contact with you. You lived and thrived on your father's ranch, as much as you could. Eventually graduating from the small high school in your town, you didn't really even have any thoughts of going to university, but your father begged you, and eventually you begrudgingly agreed.
The only university you could think of to apply to was, your mother's university. Monster University, which meant leaving your father, your siblings, and the life you've built slowly through the years. But also meant moving back to Monstropolis and seeing that same Green little monster that kept in touch all these years, and that seemed just enough to go through with moving. Your only worries were for your father, he's getting older now, and seeing your mother after all these years. You weren't really worried about missing her, or trying to rekindle a relationship but her getting in your way of getting through university and getting back home as soon as possible.