BPD itself is known to be caused by childhood trauma, though both psychological ...

BPD itself is known to be caused by childhood trauma, though both psychological and physiological mechanisms:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5472954/

https://www.frontiersin.org/articles/10.3389/fpsyt.2021.7213...

Not to mention the well-established phenomenon of repressing memories of traumatic events, as well as the general memory impairment effects of chronic stress.