Most people think of forgetting as a defect. But I consider it a great benefit.
If you did not forget, it would be utterly impossible to serve G-d. You would remember your entire past, and these memories would drag you down and not allow you to raise yourself to G-d. Whatever you did would be constantly disturbed by your memories of the past. But G-d has given you the power to forget and disregard the past. The past is gone forever and never need to be brought to mind. Because you can forget, you are no longer disturbed by the past.
This is very important to consider when serving G-d. most people are distressed by past events during prayer. When a person recites his prayers, his thoughts are constantly disturbed by memories of the past….
The best advice for this is simply to forget. As soon as an event is over with, forget it completely and never think about it again. Understand this well, for it is a very important concept. ~ R’ Nachman of Breslov zt”l (Rabbi Nachman’s Wisdom)