I don't think we often really learn from history.
Here's why we repeat history:
It is not the mere forgetfulness that drives us to repeat history, but the self-delusion that "this time, it would be different".
We may remember what happened in the past as a mere cognitive function, but may deliberately choose and will not to apply it in the current situation, pleading a different circumstance.
We are our worst enemies sometimes.
Your second question is the answer of first question.
In short, We repeat history because we did not learn from history. And history in itself gets repeated for those people who are no aware of, whose conscience has not developed to understand properly about history or about their past domain.
Everything gets dissolved with the passage of time,that is why it is called history but the main significance of history is to take lesson from it, and not repeat the same mistake, else the fate will continue to be the same.
Once you learn to be attentive, conscious and aware of, then the same mistake will not happen and history will not get repeated....this side of history what I am talking about is "mistakes".
Thank you and Have a great day.
Because you humans are forgetful, that's why
History is an activity that has happened in the past, if you mean life history maybe we should know it. For example history before there was clothes, maybe we should learn to make our own clothes from bark / animal skin.
And if you mean history falls in love and the ends are hurt maybe everyone won't want it to repeat.