Why Walter hunt invented the safety pin?

he invented the safety pin because he needed an idea to get 15 dollars.

so he was sitting at home messing with somewire and boom it came to him.

he got it patened #6281 &+ sold it to the guy he owed for $400. he had 385 dollars to spare but as the years went on he watched the guy become a millionair off his invention. sucks dont it ?