On holes in memory.
These holes are not passive, they are active.
If something in your current life fills the criteria, it will disappear too.

I have an extremely good memory.
So, it is interesting to me that I cannot remember certain things.

After my mother died of cancer, with me taking care of her the last years of her life. (much to the dismay of my life, now I am pretty much homeless) I talked to one of my sisters, who told me of some of the things my mother did. And, it was a good thing that my mother was dead, because if I had known she did such things, I would have taken a baseball bat to her. (normally I wouldn't harm a fly, and rarely get angry) You just don't do such things to a child, not even in jest.

But, the really odd thing is, I remember the conversation and the anger, but I cannot remember any of the things in the conversation.