I don't think that flashbacks require triggers. At least mine don't. I was driving to see my parents this weekend and something that happened at work on Thursday started bugging me. I've learned to drive through flashbacks, work through them and generally keep on an even keel even when it seems like all the stress of the original situation comes back to haunt me. That can be as old as nearly forty five years or as new as yesterday's news. I want to be accepted as I am. I doubt I could ever be as I want to be. I guess that what I'm trying to say is that in life you have to expect flashbacks. The main thing I've learned in what sometimes seems like a long hard life is that when a flashback happens I need to change the channel as it were. In other words I need to not let whatever, or whomever bothered me previously have the power to hurt me today. To control my actions, behaviors, and even enjoyment of life. If you feel put upon, the best revenge is a life that you live fully and happily.