Know ahead of time what the chances are of a particular effort being successful. If the odds are long, that is not a reason for not trying; it is a reason not to be discouraged by failure. For instance, sending in a resume in response to an advertised job has been studied. Approximately two per cent receive a response. That is not an argument for giving up. It means that even if you have been ignored, there need not be anything wrong with your resume. It is a matter of the odds. Sending in a couple of hundred resumes shifts the odds in your favor.