It is good to take note of those mistakes, learn from them, and move on. Continuing to scold ourselves for past errors mires us in the mud of the past and keeps us from advancing on the highway of now. We should never derive comfort from another's errors. After all, it could have been us. There is such a thing as healthy criticism.
True criticism is never emotional.
When the emotions interfere, judgment is clouded. The manner in which criticism is given will have great bearing on the way in which it is accepted. When it is given solely for correction and assistance in a friendly or loving manner, it is usually well taken. The next time you are tempted to criticize yourself or another, pause for a moment's reflection. If it is to help, make your remarks and proceed to something different.