In my latest two lucid dreams (a significant part of my LD's :p) I experienced the same thing. I just knew I was dreaming and didn't RC. The anoying thing is that I cannot recall how I figured out I was dreaming. one moment I'm just part of dream and the other moment I'm aware of that I'm dreaming and it is almost as if I knew it all along and only "played" that I didnt know
very weird... but that is what makes dreaming fun