Once again, I'm returning to January 1993 for another one of my unfinished sentences and a few of its responses...
Per Plato, "necessity is the mother of invention." This rings especially true when...
...the father happens to be conspicuously absent from the scene. (Jeff B.)
...the government @#&*s up and requires a cover-up. So far, their track record of getting away with it is pretty good. (Sean B.)
...you are confronted with a truly interesting person you want to talk to but don't know the first actual thing about. (Neil S.)