I've had quite a few cases were I cannot remember if something was a dream, or if it really happened?

It happens with thoughts too. I'll have a thought, and later I can't remember if that really happened or if I imagined it. Am I delusional?I've had quite a few cases were I cannot remember if something was a dream, or if it really happened?
YOU TRY GOING TO A DOCTOR OR SOMETHING. JUST TO BE SURE IT ISN'T ANYTHING SERIOUS