@remiska: I put "autistic" in quotes because I've seen it being overused and misused too many times to give credence to such armchair psychology.
Also, those symptoms you listed aren't unique; what you just described is someone who is very shy (first and fourth points), has a wild imagination to near-chuunibyou levels (third point), and is a geek about some atypical subject (second point). Even a cursory read of the Wikipedia article for autism tells you that the disorder is about
much more than what you're oversimplifying it to.
It's like seeing someone with what physicians call "
flu-like symptoms" and immediately assuming they must have influenza when it can be anything from gastroenteritis to meningitis or even
luekemia... or just a common cold.