Usually I only get DejaVu when I have hasded lack of sleep..But isn't that called a premonition?..
Premonition and DeJaVu are basically two things
in most cases, DeJaVu is remembering a moment of most likely dreaming without ever going over the dream.
Like you dream, wake up, don't remember, months to years later you have DeJaVu and remember the dream, but don't remember thinking about it.
Premonition is where you have a dream and you record it, then it comes true
those are my definitions, go ahead and troll me if im wrong