I think a lot of it is indeed half-remembered dreams. I've woken from dreams believing that what happened was a memory, convinced of it, even though I was aware

I think a lot of it is indeed half-remembered dreams. I've woken from dreams believing that what happened was a memory, convinced of it, even though I was aware it was also a dream. Usually this only happens when I'm physically ill (I've been fighting a bad sinus infection and I've had some hyper-realistic dreams all week).