Why can Mom remember the most negative parts of her life?

I think some people are just prone to remembering negative things, in part because of childhood experiences about what their family may never know. If a child was criticized or not treated as generously as a sibling, resentment grows and criticality can accompany it, especially toward the sibling and the parents.

Your mother may have been really hurt by some of the negative experiences that occurred, and they may have been so indelibly etched into her brain that they surface whether she wants to think about them or not.

And of course there's always the aging issue. I don't think anyone wants to experience the negative sides of aging, and it can make some people more angry than others.

Sometimes redirection works, sometimes just agreeing works, followed by a change of subject. I think it would depend on the specific nature of the negative comments (and I'm not prying to ask what they are).

Just throwing out some suggestions here...

For someone who's excessively thin and thinks most other people are fat - comments such as "I'll bet they wish they were as thin as you are", or "what secrets can you share on how you've kept your weight down?" something like that. Perhaps even asking questions can refocus from the critical mode to the thinking mode.

Others, such as "how can I help you when you think of such unfair situations" might shift the burden to them in terms of responding positively instead of complaining.

Sometimes I try to put myself in the position of the one complaining and think what someone could say that would shut me up.

I can remember the hurtful and embarrassing things that happened to me in high school like it happened yesterday, yet I can't even recall most people's names from that time of my life. I think some things are just seared into our psyche, even if we would rather they were not. Add in a negative personality and some cognitive decline and voila, you have lots of grouchy old folks who can't seem to say anything nice. It's hard to not get trapped into the negative cycle when you can't get away from it, but now that you have identified it and are aware you should be able to learn to ignore it, or at least just shrug it off after the fact.

I think my mother has two main areas in her memory. One is for remembering all the good things about her life. The other is to remember all the bad things about other people. It is funny that she will bring up something my brothers or I did 50 years ago and hurl it at me like it was yesterday. It is irritating, but given a few minutes away from her, I am able to shrug it off.

My dad only dwells on the negative in everything. When asked why we cannot talk about good things or good times or good people, he throws me some baloney like "it is too hard to remember", yet he can remember somebody who did not return a borrowed screwdriver from 1943. I have tried the redirecting too. It very seldom works, so I try to find something "benign" to talk about like the weather or what is for lunch....

Hang in there! This generation has so much to be thankful for...living through the depressions, WWII, etc, etc.....but it seems a very common denominator to be bitter about absolutely everything! It it the mercury in their dental work?????