From The Code Book by Simon Singh, quoting Martin Hellman, one of the inventors of public key cryptography:
You have idea number 1, you get excited, and it flops. Then you have idea number 2, you get excited, and it flops. Then you have idea number 99, you get excited, and it flops. Only a fool would be excited by the 100th idea, but it might take 100 ideas before one really pays off. Unless you’re foolish enough to be continually excited, you won’t have the motivation, you won’t have the energy to carry it through. God rewards fools.
Remember "Stay Hungry, Stay Foolish" from Steve Jobs' commencement speech at Stanford University? The Lean Startup?
Diffie [co-inventor] and Hellman spent month after month attempting to find a solution. Although every idea ended in failure, they supported each other and persevered. Diffie often went through long periods of barren contemplation, and on one occasion in 1975 he became so frustrated that he told his wife Mary that he was just a failed scientist who would never amount to anything. He told her that she ought to find someone else. Mary told him that she had absolute faith in him, and just two weeks later Diffie came up with his truly brilliant idea.
In other words, entrepreneurship–invention as well as innovation–is very much about learning from failure and keep going until you connect the dots.