The things most often remembered about the past are usually negative. We feel guilt, anger or resentment regarding actions taken by ourselves or others over the entire course of our lives. We can even go back in history and have these feelings about our history as a country, ethnic group or religious organization.
The really good things are forgotten. The good things you do in life are like the water soluble B and C vitamins that are flushed out of your system each day and need to replenished.
We need to keep supplying the world with good thoughts and actions every day for it to remain healthy.