My memory for events is pretty spotty (unlike my academic memory or my memory for details that may matter to me, but usually have little connection to the major events in my life, which is close to photographic). I can recall my childhood up to age 14 only in snippets, or I just have this general knowledge of how I felt back then, which seems to come from many events having become blurred together, and that's it. What I do remember vividly is usually connected to happy, meaningful things - my talks with Grandpa, the forest, animals. The rest is all but blotted out.
I don't think I ever fully forgot who I am, but I come close to it. Usually I'm stressed, sad, or simply very thoughtful (to the point of spacing out) at those times, maybe in different combinations. I'll be walking somewhere in the park and lose all sense of time, as well as any sense of connection with everything outside what I can see and touch there and then, - it's as if the place where I live, my family, university and everything else has never existed, or perhaps it did in some dream I had ages ago and had almost forgotten. I drown in my surroundings.