One of the most useful words that I've been fixated on for a while is "retcon". A
portmanteau of "retroactive continuity", retcon comes from the world of comics and represents the idea of "correcting" past facts to represent a new desired reality. The word has long been in usage, as is predictably well-documented on Double-Tongued Dictionary and Wikipedia
In comics, of course, this is fairly harmless. In TV, as when it turned out that it was all a dream, it's downright entertaining. But we see retcons in the world of business and politics more and more frequently.
Usually, the criticisms of retconning in the real world are that it's, well, Orwellian. Politicians in particular seem partial to especially heinous misuses of this technique. But the idea's captured my imagination because it seems like there may be some positive reasons to bring retconning out of the comics closet and into the real world.
Basically, a lot of us spend time lamenting mistakes or regretting bad decisions or bemoaning missed opportunities. But there are many, many times when it turns out that something that seemed like bad news at the time turns out, in retrospect, to be for the best.
And in particular, I find that many of the most successful people I know are those who are able to look back at events in their lives and rethink them in a new context, to turn defeats into victories on the strength of the lessons learned. It's the same creative impulse that motivates people to create new worlds through their creativity, ambition, or artistic ability. In the pages of a comic book, or in turning the inevitable setbacks in life into learning experiences, retcon is the way we (re-)invent the universe.