A second lieutenant, looking crisp in his gabardine and khaki uniform, sat in the front row. He had just graduated from Officer Candidates School, and would escort us on the hour's drive to the Marine Corps base in Quantico, Virginia. Shortly after we pulled away from the recruiting office, he stood in the aisle and turned to face us. I expected a welcome, a joke, some commiseration.

"Honor, courage, and commitment are the Marines' core values," the lieutenant shouted over the engine.

He sounded scripted, but also sincere. "If you can't be honest at OCS, how can the Corps trust you to lead men in combat?"

Combat. I glanced around the bus's gunmetal interior, surprised to see people reading or pretending to sleep. No one answered the lieutenant's question. He stood there in the aisle, glaring at us, and I sat up a little straighter. The lieutenant was my age, but he looked different. Shorter hair, of course, and broader shoulders. It was more than that. He had an edge, something in his jaw or his brow that made me self-conscious.

I turned toward the window to avoid his gaze. Families drove next to us, on their way to the lake or the beach. Kids wearing headphones gawked, surely wondering what losers were riding a school bus in the summertime. A girl in an open Jeep stood and started to raise her shirt before being pulled back down by a laughing friend. They waved and accelerated past. I thought of my friends, spending their summer vacations in New York and San Francisco, working in air-conditioned office towers and partying at night. Staring through the wire mesh at the bright day, I thought this must be what it's like on the ride to Sing Sing. I wondered why I was on that bus.

I went to Dartmouth intending to go to med school. Failing a chemistry class had inspired my love of history, and I ended up majoring in the classics. By the summer of 1998, my classmates were signing six-figure contracts as consultants and investment bankers. I didn't understand what we, at age twenty-two, could possibly be consulted about. Others headed off to law school or medical school for a few more years of reading instead of living.

None of it appealed to me. I wanted to go on a great adventure, to prove myself, to serve my country. I wanted to do something so hard that no one could ever talk (expletive) to me. In Athens or Sparta, my decision would have been easy. I felt as if I had been born too late. There was no longer a place in the world for a young man who wanted to wear armor and slay dragons.

Dartmouth encouraged deviation from the trampled path, but only to join organizations like the Peace Corps or Teach for America. I wanted something more transformative. Something that might kill me — or leave me better, stronger, more capable. I wanted to be a warrior.