Something weird happens to me

Sometimes, I have weird flashbacks. Like, I couldn't even describe them. They are so familiar, seems like I have actually lived them but I couldn't say if I really did, or if it's a dream, or something I've seen on the TV or anything. Anyway, there I am feeling all dizzy and feeling like I'm about to throw up (which I even did once). It lasts like a few sec-1min and then it's gone. And I can't remember or describe those flashbacks now that it's over. What do you think? Have you ever experience something like that?

(excuse my english I'm french)