Thomas Edison was a firm believer in the importance of failure. Failure was what led him to success. Once, when he was working on developing a better battery, a discouraged assistant came up to him and suggested that Mr. Edison must be ready to quit after having performed some 50,000 tests without success. "You must be pretty downhearted with the lack of progress", the assistant said. Edison replied, "Downhearted? We've made a lot of progress. At least we know 50,000 things that won't work!" In the end he developed a nickel-iron alkaline battery that became an industry standard and is still used today-more than 90 years later!
If Edison had let the 50,000 failures get him down, we might not have that battery today. It took more than 2,000 tests to find the right filament for the light bulb.