Generally when I wake up and have been dreaming I remember mostly feelings and the odd stray thought, very rarely have I experienced a vivid dream which stays with me once I awake. I normally know when I dream just not what I've dreamt, it's a specific feeling which comes to me as I begin to awake that gives it away for me.
Last night I had a dream which left me with a few sparse notions just as I awoke. It's strange how your subconscious twists things together on you.