You are not going to win or succeed every time.  In fact, in life you, me and everyone will encounter more disappointments and failures that successes.  Simply accepting this reality actually makes life easier.  It takes some of the pressure off.  It gives us a better perspective when we don't succeed. We can shrug off the failure as a common feature of life rather than being devastated.  A healthy and realistic expectation also makes the failures sting less and avoid seeking someone or something to blame.  It also helps us avoid a victim mentality (that all the world, society and people are out to get us) which is devastating to our happiness and future success in life.  So knowing I'm going to have some setbacks, what is the key?  Keep going!  Failure is a temporary milemarker on the journey (the long, difficult, hot journey) to success.