Human resilience includes the ability to take a failed idea (or even a successful one) and use it for a completely different purpose. It happens all the time. The new purpose then become the main purpose, and the original intent is often forgotten. You've read about the origins of some these things right here at Neatorama, but there's always something new to learn.
See all 18 pictofacts about repurposed objects at Cracked.
the prisoner is anyone who's ever owned a treadmill
hard to get rid of