When you should on the past, you have no recourse because there is no way to change the past. Reviewing doesn’t really help except in one way: It might be helpful to learn from for future use and strategizing.
An example, that many people regularly do, is with an embarrassing conversation. We can review this conversation, like an internal movie, and recall every word, expression and action. We can entertain alternative ways to react, or “I should of saids.” The regret and review only serves to torture you. We relive the past feelings that went along with the interaction as well or even worse emotions. Thus, a case to should less about the past.
My daughter came up with a great perspective towards regrets of the past and it involves sorting the recycling from the trash. The recycling is the lesson learned, the if/then programming that you can incorporate going forward. The trash is the continuous rumination on what you should have done, said or otherwise. This replaying of the past only serves to torture you and/or others.
Should less?