Subject for future investigation

Why exactly is it, that sometimes when I pick up a guitar after not playing at all for a while (in this case, several weeks at least), I can play far more fluidly than usual? Especially if not playing that close attention, e.g. while watching a movie at the same time. It's as if my fingers do better if my mind is not watching them. The moment I start paying closer attention -- or even more, if I try to consciously shape what I'm doing -- the fluidity starts to drop away. What, in fact, is going on there?