Roomer

Refers to someone who typically stays in their room for over two thirds of their day in their room, hence the name. Roomers neglect the outside world and usually have an attention span that is too short to allow them to effectively accomplish anything they want to do and will usually fantasize about any possible future accomplishments they wish to achieve.

Guy 1: "My god I'm starting to get sick of Jack staying in his room all day."
Guy 2: "He's basically a roomer at this point. We're probably never going to see him again."