Fret, worry, anger, anxiety, your emotions are on automatic. Your memory, mostly images, or thoughts without form, seem to initiate emotional reactions in the same degree as actual reality. Naturally, memories are desirable in order to learn, and to not make the same mistakes over and over.
The flaw, I think, is that the memories cannot just be perceived dispassionately, instead they reignite the feelings felt at the time. If it were possible to look at them as pictures, as simple information, then the additional stress associated with the original real encounter would not be relived. Though such an ability may not be included with our software, the ability to learn exists. Perhaps with repetition and exercising will this software can be altered.
The wear and tear on an organism from the initial emotional encounters should not have to be compounded by reliving them every time you view your archives. All of this could be rendered moot if our minds possessed a delete function. However, try as one might, neither our minds have it, nor do humans possess the technology to erase memories. Besides, how can a lesson be learned if you forget it?