I work in the mental health field, where many of our clients are extremely poor historians. Intake interviews can sometimes be entirely useless, as the information provided is often conflicting, contradictory or else completely nonsensical. If I couldn't trust my own memories my identity would likely be altered beyond recognition, or perhaps, completely wiped-out. Not a pleasant thought to contemplate, which should give those who do have sound mental health all the more compassion for those who don't.