More recently in my meditation practice the following three-stage phenomena has occurred -- I will sit for a 20 min. session, at first I am focusing on my breath, then my breath seems to "guide" or "carry" my awareness of my surroundings as well as my own body (e.g., sort of "matching" my breath to my awareness of everything around me...if that makes any sense), and finally I start to see everything (my own body and surroundings) from the perspective of an outside observer...very similar to the feeling of watching a movie except me and my surroundings become the movie.
The last part is what elicits some fear. It really feels as though I am "letting go of myself" during these experiences, which seems to be the goal of zen, but at the same time I start fearing that prolonged stays in such a state will cause me to "forget who I am" which makes me worry about my interactions with other people and how I might come across to them (e.g., my wife).
Does this make any sense? Has anyone had similar experiences?