I've been having problems with this in recent times. Exam stress, final drafts of coursework, essay deadlines, etc. With no real coping resources or social ties the stress of it all makes me bury my head in the sand and disconnect myself. The shame of missing deadlines and the added pressure of new ones approaching makes me bury my head deeper. So much so that I missed the final deadline for a piece of coursework when I haven't even handed in the first draft. Yet for some reason, I just don't care.
I'm not sure if this was what you're referring to. It sounds a bit maudlin, I know. I just don't have the incentive to come out of my shell.