Twenty years ago today - the Ides of March, 2002 - I enlisted in the Army National Guard. Unlike most of the young men and women going through in-processing that day in Boston, I was already a college graduate, I was already married, and I wasn’t exactly young. I was twenty-eight years old. Had a full-time job as a software engineer, had a mortgage. What motivated me to join was a sense that I could be doing more to serve others.