"This lemon tastes just like vinegar."
"No, no... it can't be a unicorn!" followed moments later by, "Yes, yes! It is a unicorn!"
As a teenager, I had a daybed, and would frequently leave empty soda cans and water bottles precariously perched on the frame. One night, I'd made the mistake of leaving a not-quite-empty water bottle near my pillows, without a cap. I woke up a few hours later after dumping what was left in it over my head. Another time, I woke up just as I was punching the wall next to the bed, Kill Bill style.
My fiance and I have also woken up in the middle of a conversation, though neither of us can remember what exactly was said.