We failed so many times. Gemini 8 Neil Armstrong almost died due to a thruster misfiring. While Ed White's first spacewalk went really well, the next three attempts were failures until Buzz Aldrin decided to train in a pool. Then there were the computer errors from Mercury to Apollo, even minutes before the first landing on the moon, "1202!... 1201!"
I have watched the series several times, it's really good. Yet I seriously did not realize until tonight how often we failed in the early years. Sensors failed. Control systems gave the wrong angles. It's amazing that it took until 1986 for a rocket with Americans to blow up at launch, I mean Orbital Sciences just had one blow up this week. SpaceX I think had their first three rockets blow up and Elon Musk gave a speech to the team at the time saying there was only money for one more shot, and they succeeded!
In my short engineering career I have learned that development is like that. We try something, hopefully it works, but inevitably it fails. You might be stunned to know that billions of dollars a year are spent on products and prototypes that are inevitably scrapped or left to rust or simply destroyed as examples of insufficient designs. There are no perfect designs, although some are clearly better than others.
The moral of the story is it is okay to fail. Preferably fail fast and fail early although anytime you try to do something new, it will be hard.