Agree with the trauma that people with Dp either forgot or deny. Not through any conscious control or choice, but it seems very strongly denied even as a possibility here quite often. The disorder wants to be objectified (and I did that for a very long time). It wants to be made into a chemical imbalance, or vitamin deficiency, or fixed through meditation, exercise, diet or yoga or something that will physically 'fix' us.
What makes this worse is people come here with 'cure stories' who had intermittent DP for 2 months and fixed it by doing one of the above. But how do we even know they had DPD? They probably just had burnout or anxiety which only needed a short amount of time to fix. DPD itself is largely related to trauma I think, it is a dissociative disorder primarily and even when it is caused by a panic attack on drugs I believe that is still the route cause.
Not to say there are those who experience chronic derealization as a result from vitamin deficiency or depression/anxiety.... but there comes a point when people have to be honest. I was told my childhood was perfect which almost prevents you from revisiting negative memories. Through therapy I have started to process this and seen my DPD is a result of C-PTSD. Talking through these memories, grounding and reconnecting with emotions are primarily what are going to 'fix' me