One of the common denominators of successful people is their ability to persevere when things don't go as planned. Effective people don't allow themselves to get bogged down in feelings that don't serve their purpose.
On the other hand, ineffective, unsuccessful people allow their emotions to rule rather than their rational and objective nature. They lament what happened or what didn't and become victims rather than masters of their circumstances.
We all have disappointments. We all suffer setbacks. If we're going to attempt anything worthwhile, we're going to experience failure. The mature—and ultimately successful person—sees failure as part of success. When one method fails, they try again with a new one. Sometimes it takes many attempts.