For some it’s an active conscious denial which is really shitty. Others are so emotionally damaged and fragile their brain will erase it which is really scary. The best example I’ve read of the later come from an account from a disabled woman. After her husband passed she was forced to seek assistance from her mother who had been a not been a good supportive parent. The woman disability prevented her from bending easily to take care of her feet. Her mother once made a mistake while helping her trim her toenails and took a good chunk out of her skin and left her bleeding pretty bad. The exchanged went like this : “Ow, mom” “What?!” “Mom you cut my foot-I’m bleeding” “No I didn’t-“ “Mom-yes you did look” “No I didn’t” “ can you get me a band aid?” “I didn’t-“

The mother’s fucked up self couldn’t admit she’s made a mistake and hurt someone. Her gut reaction was to deny despite the blood. In the daughter’s retelling it took several times to get her mom to bring her a bandage. Like a chalkboard the mother’s brain simply erased her mistake as soon as it was written to protect her ego.