[Building a phonograph prototype] I then shouted, “Mary had a little lamb.” I adjusted the reproducer, and the machine reproduced it perfectly. I was never so taken aback in my life. Everybody was astonished. I was always afraid of things that worked the first time.
This is how Thomas Edison described his first experience building a phonograph for storing and reproducing sound. The astonishment mirrors the sentiment of many tinkerers and engineers around the world who often hope but never expect things to work on the first try.