One thing my own career has shown me, again and again--if you don't get a job, university place or other competitive position you apply for, write a respectful letter to the person who informed you of your non-selection and ask why you were not chosen. Then ask how you can make your credentials stronger to apply again at a future date. Sometimes you'll get no response, but other times your added effort will put you at the top of the alternates list, and maybe get you a second chance if the preferred candidate backs out. If you can make a call on the phone the person who rejected you, that's even better. Just be sure you don't communicate anger or hostility. Instead, communicate humility and a sincere desire to make changes that will make you a better candidate. I have gotten several jobs by doing this, as well as referrals for other, similar jobs. This is called networking--making friends in your desired profession. Naturally you will do the same for others.