The past is a foreign country, they do things differently there. - L. P. Hartley, The Go-Between, 1953.
I ran across this quote in a podcast talking about how an historical event still has repercussions today. But the thing that rang for me is related to another book I have been reading about the way we think about the world. In our minds, we tend to think things are very much like they are today -- that the way we do things and the way we think about things now is the same as it was 5, 10, 100 years ago. But it is not the case. The world changes. Technology changes.
Think of all familiar practices and policies - written and unwritten - that govern the way we operate. All those things that people say, "That's the way it has always been" are only true because they don't know (or don't remember) what it was before. Does it need to always be that way?
If we can understand some of the reasoning behind these things, we can ask whether those policies or practices should still be in place.
Why? Because those policies and practices often block improvements. Your classic claim that "people resist change" often comes from these hidden beliefs about the world -- on both sides.
Put on a different hat, and think about how things are different in the past. What was the currency, the language? This can help see why these practices and policies came about.