It is well-known that memory is selective by its very nature.
There are things one remembers easily, there are things one would like to remember, and there are quite a few things one would like to forget.
What a person remembers is, to a large degree, a true indicator of his essential nature and character.
It is told of one sage that he would ask those who came to him only this question: “What do you remember?”
According to the answer, he would evaluate the person’s nature.
One of the problems with memories of any kind is that they tend to distort the past in order to compare it to, and bring it into line with, the present.
For this reason, absorption in and reflection on memories are not necessarily beneficial to one’s personal development.
Not infrequently, the “wisdom of hindsight” enlightens and clarifies nothing.
However, memory can indeed become a source of greater understanding if one emulates the Holy One, blessed be He, who “remembers all the forgotten things.”
As our sages explain, God remembers the things that man forgets.
If one forgets his sins, God remembers them for him; and if one forgets his merits, God remembers them, too.
In other words, there are things that, for various reasons, a person does not wish to remember – errors in judgment, errors of commission, mistaken conceptions.
It is precisely these things that one must remember especially!
–Rabbi Adin Steinsaltz