Memories are essentially stories we tell ourselves about the world. They’re not real records of events, they’re condensed down into a narrative. Stories are how we understand the world. It’s hard to fault you for picking up on the meme of Manifest Destiny; at least you’re self aware about it.
Sometimes I tell myself I may as well change some bad memories to be better. If I manage to accomplish that, I can change the past. Because the only record of some of these events is in my own brain. I am the arbiter.