We’re used to the future turning out differently than we expected; it happens all the time. When the past turns out differently, though, it can get really upsetting, and because people don’t like that kind of upset, we’re at risk of finding new reasons to believe false things, rather than revising our sense of what actually happened. (The Failure of #amazonfail)
On a related note, the tag options for these nomadlife posts are out of control. I vote for jesse to summarize them with thrice an option, in portanol.