What does it mean when someone has deja vu?

Simple.

Our brains are designed in such a way that it stores most of the day-to-day information in generalized groups. Our brains also like to run scenarios (mostly the lymbic system's fault) for the purpose of composing plans (I like to think of them as "in case sh*t" plans).

So how does this apply to deja vu? Because our brains are designed the way they are, they tend to subconciously run un-important scenarios with random bits of information. We don't conciously think of it (or its such a normal routine), so most of the time we don't realize that our brain already thought about what is going on in regular situations.

Every once in a while though, our brain runs a strange scenario that might happen in our life, but probably won't happen as exactly as it ran in the brain. Because it was such a strange coincidence, our brain recalls the pieces (because we now are consciously pulling it out of our brains "random cr*p" bin). This is Deja Vu.

This is similar to what happens when we dream. Random stuff being randomly accessed as the brain is doing its regular thing. This is why some people feel they dreamt a situation.

Deja vu is usually when our brains are stimulated in telling us that we have been at a certain place at a certain time more than once, meaning if you happen to be standing at the edge of a cliff, and your mind says you've already lived this moment, then you feel stimulated in believing so, and ironically come to conclude that you've lived that moment more than once.

Deja vu is French for already seen. that's used to describe a feeling you get once you're saying or do or see something and sense which you have achieved that previously or been there previously.

Why do I have the feeling I've already explained this? Just kidding. Uh, truth to tell, I've never heard that right place/right moment wheeze before. I've heard that it's a momentary tear in the multi-dimensional/universal fabric, where you become partially aware of one of your other selves. And some regard it as a momentary remembrance of another time, perhaps a past life. I myself, and most modern scientists (spoil sports) consider it to be neuronal misfiring, a sort of synaptic hiccup. Maybe it's none of'em, who knows.

I always thought deja vu meant your life was on track. I think it is true.

no

it like when you have a dream

and you actually feel like you were there when you are a wake

whether it doing something walk in some room

when i have deja vu it just gives me a heads up of soemthing that gonna happen

like i had a dream that i was at school passing by this building that i usually dont pass and my then boy friend was with his ex

well a week later after we broke up i decided to walk that direction and i saw them walking together

No matter what, in the moment you decide, you will see that the same things do happen twice, in a way, otherwise could we really have time?

I think I've answered this question before. :D