Is amnesia symptoms two months post concussion dangerous?

Many types of forget. If you mean that you do not recall portions of time when the injury itself occurred - that is not unusual. If you have persistent problems with memory in general sine the injury, that is a TBI (traumatic brain injury) related memory problem. Amnesia is a lapse in consciousness that disallows any (or most) recall of what had happened. One might come to and not recognize where one is. Do not drive.