Secondary citizen

For the last several years, almost every time I clear security at US airports, my boarding pass is marked “SSSS” and I have additional security screening. I am called a “Secondary”. I have asked for years why this always happens to me and no one has an answer at the airport. Thus, I am turning to the Internet to see what I can do to stop hemorrhaging time on excessive security checks. Or is this my fate as an international man of mystery?