My little brother is a weirdo

They say that first impressions are important,but that's not always the case. Your first impression of someone could be that they're extremely pleasant,but overtime as you get to know them you realise that they are a complete psychopath. They could have a fetish for eating dog food or hide mole people in their basement. Sometimes you would stay friends with these people out of general loneliness, but for those who would rather avoid them,I can assure you that it will be difficult. Why, because everywhere you go, you meet these people. At the beach, at the fair, at a convention held by your university professor on the evolution of moles into a sub-human species or even at a salad one, although the last one seems quite far-fetched. These people could be your lab partner until the term ends or move into the creepy abandoned mansion down the street (quite a good deal if you ask me,it comes complete with its own built in cobwebs and random thunderstorms) which is exactly the case in this story. Sometimes it best not to socialise,after all there's always a reason people move away.

(The story might not match the description as I'm making it up as I go.)