what can history teach us?

This is a huge open ended question, but I’ll put in a comment. Generally we are supposed to learn from our mistakes. For many, history is supposed to be a cautionary tale. Unfortunately we keep making the same mistakes over and over. Wars, genocide, starvation.....are all repeated throughout human history. Having said this, history can teach us who we are. Humanity is made up of our collective experience. Though we may not learn from our mistakes, history is always interesting!