I had never read that before, thank you. It is strange how readily accepted it is that ideas belong to their inventors by natural law, given that the Constitution explicitly states that copyrights and patents are "for limited Times" and "To promote the Progress of Science and useful Arts" (i.e., primarily for social benefit). I think people like to fantasize about the One Great Idea that will make them rich, and that fantasy has become part of our cultural narrative.

Also relevant, of course: how often an idea doesn't come to just one person: http://en.wikipedia.org/wiki/Multiple_discovery