I have to agree with Orange Blossom-it's like a bolt of lightening. I'm blasted right back to where it was happening, I'm completely unaware of everything except being right in the middle of the trauma. Then something changes and I'm back to the current. Usually something triggers it to start (a smell,a sound, a feeling), but sometimes I don't know what starts it. It makes me feel so crazy, when it first happened I was ready to go the ER and be admitted for hallucinations.