How are you sure the history told to you is not just a redacted version of the victor?

How can history really be trusted when the victor is the one that more than often gets to write it? Imagine if Nazi Germany had won, history at least in areas they controlled would have been told a lot differently. The Holocaust might have even been lionized. The struggle to take the West from the Native Americans, all the double dealing never made the history books but most all the “uprisings” as they call them spawned by the double dealings I am sure did, and not in favor of the Native Americans. How do you know the history you get is the ”real” history and not a redacted version of those who came out on top and was able to direct it?