“If you are defeated once and tell yourself you will overcome, but carry on as before, know in the end you’ll be so ill and weakened that eventually you won’t even notice your mistake and will begin to rationalise your behaviour.” Epictetus, Discourses.
Even in defeat, resist the temptation to rush towards feeling in control again (painful, though it is) and instead take the time to look at what you want to achieve, what you did and what you could do differently next time. Perhaps the end goal has changed? Perhaps you could try a different approach or use some new skills?
Chance or ‘luck’ still play their part out of your control, but one thing you can be sure of is this: that doing the same thing again and again and expecting to get a different result is close to a definition of insanity. Break the cycle, otherwise you will be that solitary unclaimed suitcase going round and round on the baggage carousel of life.