I love the illustration John Maxwell uses about failure in his book Failing Forward (p. 47-48),
Four monkeys were placed in a room that had a tall pole in the center. Suspended from the top of that pole was a bunch of bananas. One of the hungry monkeys started climbing the pole to get something to eat, but just as he reached out to grab a banana, he was doused with a torrent of cold water. Squealing, he scampered back down the pole and abandoned his attempt to feed himself. Each monkey made a similar attempt and each one was drenched with cold water. After making several attempts, they finally gave up.
Then researchers removed one of the monkeys from the room and replaced him with a new monkey. As the newcomer began to climb the pole, the other three grabbed him and pulled him down to the ground. After trying to climb the pole several times and being dragged down by the others, he finally gave up and never attempted to climb the pole again.
The researchers replaced the original monkeys, one by one, and each time a new monkey was brought in, he would be dragged down by the others before he could reach the bananas. In time, the room was filled with monkeys who had never received a cold shower. None of them would climb the pole, but not one of them knew why!
I wonder how many things in life I am too scared to try, not because the task is impossible, but because I have just never evaluated if there was a better way of getting it done.
NOTE – after further review it looks like this experiment never really took place…but it sure makes a great point, right! (See comments for some great links)