This is a good question. There is a maxim that states: "Those who do not know history are doomed to repeat it." There is a lot of truth to this. If we do not know what has happened in the past, we will not learn from the mistakes and even successes of a past generation and this can hurt us. In light of this, knowing events of the past can help people who have a willing heart to learn and grow in wisdom.
With this stated, we cannot be certain that people will learn from the past and act accordingly, even if they know past events. Think of some of the atrocities of recent history. It is clear that we have not learned all that much from the past, even if we know our histories. Let me give one example. All know that greed is a bad thing and yet our financial companies are still very much about greed. To be more pointed, if we all know that it is not good to have banks that are too big to fail, then why are our banks even bigger now?