The winner of the race is not always the fastest runner, it is not always the most prepared, nor the one with the best shoes, but it is always someone who finished. Perseverance (aka stubbornness) is one of the most overlooked character traits in the hiring process, but it is one of the most important indicators for success on the job. This is especially true of high stress, high risk, and high return potential jobs. It is almost a cliché that the higher the value the harder it will be to do. Achieving great results usually means several cycles of failure, retrospective, and retry. Well-known inventors and entrepreneurs all have stories of failure, usually several times before succeeding. It is not the vision to dream which is hard, it is the courage to see your dream shattered, learn from it, and dream again that achieves greatness.
Some of the best advice I was ever given: there is nothing more devastating than a life with no failures because that is a life waster. Go ahead and grieve, it is natural, but then take a look at the situation. Learn from the failure; that is the only important thing to do. Trying again is not necessary, unless you decide on a different path to take. Remember Einstein’s definition of insanity: doing the same thing repeatedly and expecting a different result.
A certain amount of wisdom is required to recognize what is really possible and what is not. Usually though, the reason we failed is because we really did not think and act early enough or insufficient quantity, and sometimes the reason for that is because we really did not care. So look carefully at why you think you failed, and plan what you can do about it.