Human memory is not an immutable record. It's not something you wrote on a piece of paper. It's more like a meal that's been digested, and now we're trying to figure out what it was originally.
Some things go through the digestive tract relatively unscathed, and so it is with memory. A few kernels get through exactly as they started, but mostly it's a mushy mass hardly anything like how it started.
We're better at looking at the digested contents of our minds and figuring out what produced them in the first place than we are at looking at the digested results of our meals and figuring out what we ate. We're so good at it that most of the time, we really do deduce something pretty close to the original. I bet a few people can figure out what the food was by looking at what came out the other end too. That doesn't change the fact that what we're looking at is not the original, and what we make of it is a result of our own experience and perceptions at least as much as it is a result of what's actually there.
More than once I've reviewed what I remember in light of what I've learned in the meantime, and I've come to a different conclusion about what the original was. I don't think I was "wrong" before. I think that my memories are mine, they mean what I decide they mean, and I can change my mind.