Germany probably shouldn’t forget the genocide of millions of people from a variety of groups, just as the united states should not forget the systematic enslavement and repression of millions of people, who are also americans and their descendants are alive and numerous today. It doesn’t really make sense to me why people should forget that, and it cannot be forgotten by the people still living with the consequences of it today - but I’m not really willing to be baited into this type of discussion on a platform like this, so I’ll just say your fundamental premises in your post sound flawed if not extremely troubling in what you seem to be implying. It sounds completely unreasonable to say for instance, indigenous groups should forget they were pretty much wiped out by largely white colonizers. This isn’t a political statement, it’s just a matter of fact.