Just an idea: Maybe sometimes we cannot trust our own mind. This sounds a bit like deja vu for me. (Warning, dangerous second hand knowledge incoming) - I once read an explanation for this feeling that it is basically a wrong connection built up in your brain, which in your perception plays out in a way that it already happened.
Don't want to jump to conclusion, just a thought to consider. We cannot always trust our own perception, as there are things that can go wrong.