At the moment we are overwhelmed to the point of shutting down, we are experiencing something categorically traumatic. Whether we experience shutting down as floating above our bodies or mentally disappearing into a happier time, this is what our body has determined is our best chance to get through this. And so our bodies get floppy and limp, we curl up, we faint, we dissociate (present in the body, but elsewhere in the mind), or more commonly, we feel like all the life has drained out of us and it is easier just to stay in bed all day.