In the past when I think I am lucid dreaming I will "test" this by attempting to fly which would be proof I am dreaming.

I have noticed that at some point if I try flying higher and higher I will begin to feel some "resistance" for lack of a better word. Almost like trying to walk through very deep snow or swim through mud. Usually I will see an image of a ceiling or perhaps cloud cover when I feel this resistance.

If I can clear my mind I can eventually push through this block and then can move freely.

Has anyone else experienced something similar? I always wondered if what was happening was separating from my phsical body while dreaming.

Last night I dreamed I was trying to fly from inside a house. I reached the ceiling of the room I was in and slowly passed through it like a ghost might- however it did not happen quickly or naturally I had to really focus. On the next floor I saw a door going outside but when I opened it there was another door behind that door. I'm not sure if I have a specific question about this particular dream but the imagery of passing through the ceiling made me recall the resistance I feel in just about every flying dream I can remember.