Hmm:
This remnds me of a gentleman whose name I cannot recall who worked with Rob Ballard - the guy who located the wreck of the Titanic. He was one of the men who planned and set up searches and had an interesting philosophy when things went wrong.
On one occasion, after a search had proved fruitless someone said "that was a waste of time, we found nothing." His reply?
"Yes we did: we found out it wasn't there."
On another occasion when confronted with something totally unexpected his take on the setback was "Wow!- now we are going to learn something"
Setbacks can be stairs or walls - it depends on how you look at them.