Human memory is always having to contend with the power of suggestion. There ought to be a lot of individual variability in the susceptibility to false memories. Maybe it correlates with genetics, intelligence and other individual differences. Perhaps we'll develop recipes for what works with various personality types. It must be threatening to a lot of people, to think that their memories aren't their own.
Memory is creative.
There, I've said it all. But human memory isn't supposed to be creative. Facts are facts, and the past is finished. So when memory scrambles things, you get annoyed. I was very annoyed when my laptop's RAM started to shuffle the files on my hard disk.