I think it's because history gets distorted. Truths are bent to conform to convenient ways of living, thinking, being.

I used to think life was just one damned thing after another. Now I think it's the same few damned things over and over and over. People are very slow to learn, perhaps because they like the world the way they know it and don't want it to become different.

because people think they know best what to do and that there situation have nothing to do with something what happened a long time ago.

The other reason is that to much history gets lost because people don’t understand why it is so important to know our history.

We need to know your history because otherwise we would do the same mistakes the same discoveries over and over again, which means that without history we would fall back into middle age or even further. ( Civilization exists as long we remember man kinds history)

I think you can observe this in people's lives as well - that children, for example, repeat the same mistakes as their parents - and that the larger phenomenon of nations and regions of the world repeating the mistakes is just a logical extension. Of course, many people are able to break the cycles that they have inherited, but this is very difficult to do. I think breaking the cycles that humanity constantly goes through is also hard. It takes a fairly brutal acknowledgment of the way things really are, along with a willingness to say no to something that you are convinced that you either need or deserve.

I think it's because people listen to history but can't identify the repetition unless it's in hindsight. Not many people apply what they learn from history to real life either.