One tired cliché is that those who do not learn from the past are doomed to repeat it. The implication is that we should remember every historical event and process and cumulate them. While there is wisdom in not throwing away historical knowledge embodied in traditions that are passed on to us, there is also wisdom in knowing when to let go. This is especially true as the past has a large set of historical sore spots and recriminations from one group against another, sore spots and recriminations that are largely uninformative about how to best move forward.
As an economist, I have to provide an answer that will make the non-economist sigh: Economic growth is the way to let go of some of the deadweight that history forces us to carry.
Go ahead, sigh! But before you do, I urge you to consider the following examples.