Have you ever confused something that happened in a dream with a real memory?

yes

There was a recurring nightmare that I couldn't sleep, but then I woke up and realized it was only a dream.

Yes!!Excellent question.A dream can be so vivid it feels real.

Yes, but only a few times in my whole life - it happens very rare.

Lol— how would I know? I’m confused

All the time

Nope.