As others have pointed out on this blog, writers have some pretty unique aspects to our lives. How many "normal" people completely lose track of the seasons, for example?
I don't know if this happens to others, but I can get so involved in what I'm writing--describing a snowstorm, for example--that when I finally look up from my work, I'm surprised to see that the "real" world doesn't match the world I've been living in. Instead of a foot and a half of snow on the ground, the May sun is shining, trees are blooming, and the un-air conditioned room is over-warm. A villain is not bearing down on my house. And the hero is not in the upstairs bedroom about to burst into fevered ramblings resulting from the injuries he sustained in the last confrontation with the bad guy.
It takes some time to pull myself out of "story world," as I call it, and into this world. Sometimes I don't want to come back.