Ceci n'est pas un rêve.
Last night, I dreamt that I got out of bed and walked into the bathroom for a glass of water. After bending over the sink to fill the glass, I looked up into the mirror and saw my reflection, and something (I don't know what) triggered in my brain and I realized I was asleep. Looking into the mirror, I started shouting "Wake up!" over and over; each time I shouted, my reflection changed into a mask-like caricature of a different emotion. This happened a dozen or so times. Then I dreamt that I woke up.