Not making the call frustration.

[Rob1968]

Okay, I did something, and got a negative result. I think, "What did I do or not do that produced that negative result?" -(missed a call, made the wrong call, etc.) Then, I think, "What will I do in a similar circumstance, in the future? And I go on.
The next time, I use the new protocol, and I check the results - were they positive, or negative? If I'm pleased with the results, I stick with the new protocol. If not, I evaluate, modify, and move on.
The worst thing I can do is to brood over something in the past. And as a young official, this would just tie me in knots, and make me freeze up more and more, because this process is always ongoing at a pace that will wear out a person who worries too much about what he did rather than taking the experience and making the next opportunity better.
Some of the other guys have said it really well - move on. It's life.