My writing revolves around people whose past lives get mysteriously changed. For example, there is a private eye who keeps discovering that the events that he is asked to investigate never actually happened and a journalist who discovers that news events about which she has written articles never happened and apparently she didn't even write about them.
In a chapter destined for a new novel in my series I wrote about a man who got the feeling that there was something different about his coffee machine, but he couldn't work out what it was. In fact he had never previously had a coffee machine and his past had been changed, making him think that he had always had it. Psychologists have discovered that the power of suggestion and the influence of observed reality can actually change people's perceptions of their own memories, so this isn't as strange as it might seem.
I have a problem though. When I recently wanted to check on a detail in that chapter I couldn't find it anywhere in any of my computers, and yet I am absolutely certain that I wrote it.
Oh no! Aaaagh!!!