THE NAVY COMMANDERS sent the letter to my mother, but they had really been after me.

In the fall of my junior year in high school, I took the standardized Preliminary Scholastic Aptitude Test (PSAT), which most colleges use to identify potential applicants. Check the box that authorizes the testing service to release your name and the colleges hit you with a flurry of brochures, videos, applications and scholarship offers.

What I didn’t know was that the Defense Department would seize upon the scores, too. Much like their academic counterparts, the armed services pore over those scores for potential recruits. And, for …