An invention has some of the characteristics of a poem. Standing alone, by itself, it has no value; that is, no value of a financial sort. This does not mean that inventions—or poems—have no value. It is said that a poet may derive real joy out of making a poem, even if it is never published, even if he does not recite it to his friends, even if it is not a very good poem. No doubt one has to be a poet to understand this. In the same way an inventor can derive real satisfaction out of making an invention, even if he never expects to make a nickel out of it, even if he knows it is a bit foolish, provided he feels it involves ingenuity and insight. An inventor invents because he cannot help it, and also because he gets quiet fun out of doing so. Sometimes he even makes money at it, but not by himself. One has to be an inventor to understand this.