Onnit Alpha Brain The most extreme version of this is a flash-back. A flash-again takes place when the mind remembers a traumatic function without the person understanding that it is just a memory space. A person having a flash-back isn't conscious that he / she is certainly remembering something from the past-rather, it seems as if the past experience is happening again in the present. This is since the brain processes info differently during particularly demanding (or traumatic) moments.