Common knowledge.
I laughed at the guy who wrote this when he said Edison ran straight to the patent office then later stated that Tesla said someone was using 17 of his patents. OOps!

Very often the first inventor fails to perfect and discern what is the best way to use something he/ she invented. Leaving it to whither. The paper clip is a very good example. It was not much of anything and was sold to a man who simply added one half loop to the design and made millions.