J.K. Rowling was unemployed and living on welfare when she penned Harry Potter, which earned her billions of dollars.
With that rags-to-riches story as a background, listen to what she said at this year's Harvard's graduation ceremony, on the "benefits" of failure and the importance of imagination:
So why do I talk about the benefits of failure? Simply because failure meant a stripping away of the inessential. I stopped pretending to myself that I was anything other than what I was, and began to direct all my energy into finishing the only work that mattered to me. Had I really succeeded at anything else, I might never have found the determination to succeed in the one arena I believed I truly belonged. I was set free, because my greatest fear had already been realised, and I was still alive, and I still had a daughter whom I adored, and I had an old typewriter and a big idea. And so rock bottom became the solid foundation on which I rebuilt my life.
You might never fail on the scale I did, but some failure in life is inevitable. It is impossible to live without failing at something, unless you live so cautiously that you might as well not have lived at all - in which case, you fail by default.
(Note: this is a fascinating Commencement Address by Rowling - if you click on only one link today, make it this one).