Lol, my answer was also correct: The person who madeit doesn't use it, my parents bought me it, s they don't want it, and I use it but actually have no idea how it works.
And in respose to zocc1, it depends. Book or movie? Because, if it's the book, the answer it Paul Benjamin, but if it's the movie, the answer is Paul Kersey.
WD-40 literally stands for Water Displacement, 40th attempt. That's the name straight out of the lab book used by the chemist who developed WD-40 back in 1953. The chemist, Norm Larsen, was attempting to concoct a formula to prevent corrosion -- a task which is done by displacing water. Norm's persistence paid off when he perfected the formula on his 40th try.