The primary reason for me, that I've ever questioned my own memories, is as a result of therapists so often doing so. For them it's in part because they worry they may be encountering an example of so-called false memory syndrome (even though I never forgot what happened in order to only remember it later in a questionable way), but the end result for me is that in having to repeatedly re-quantify these deeply definitive experiences in these settings, it can wear down on my own orientation with them.

The other thing to consider with regard to this question is that the way traumatic memories are stored is different from other memories; because we become sort of frozen in those moments, experiencing shock in real time, the memories have sort of a movie-like, or slow-motion quality, and as a result we don't talk about them in the same way. When we re-tell them it can sound like a third person experience, which can also confuse people about their validity. Therapists are always telling me it's surprising to them that I don't express the types of emotion they would expect when I share about my traumatic experiences, but that is what shock is like, and at least in the way it has felt to me: deeply embedded traumatic experience is shock made permanent.

In that traumatic memories tend to feel very different even to us than our regular memories, it's only natural that there can be a feeling of "unrealness" to them; in some cases we've been able to dissociate at the time, so that we really were there but not there; or there in a uniquely different way.