Plenty of people get flashbacks without ever having taken LSD - usually of some particularly traumatic experience - eg warfare being the classic, but also life threatening situations, rape, sexual abuse as a child etc. I've also had quite a few women tell me about vivid flashback experiences to childbirth, often around the child's next birthday. I suppose flashbacks differ markedly from feelings of deja vu or simple memories as they tend to arise fully formed and intense. Whether LSD flashbacks or tripbacks as I might call them are identical, I'm not sure. Anyone had both forms of experience that can shed some light??