Over the years, when you hear of clever ways people made money, don’t you often think, man, I wish I would have thought of that. Post-it notes, for example. Stuff like that, which people buy in bulk once it’s invented. Ideas just waiting to be found, floating around in the ether. Do these rich inventors just sit around, trying to think up this stuff, or does it just come to them in a dream? I wish I knew, because I could use a few spare ...