Looking back now from the sixth anniversary of the attacks I can say it was when she finally reached me, and I heard the panic in her voice, that I first realized I was no longer a Marine living in peacetime. In the uncertainty of those first moments, as I took stock of my Marine gear in my parents’ garage, the military as I knew it was gone forever. I had no idea how much I would miss it.

When I enlisted in the Marine Corps Reserve in 1999 I was hard-pressed to think of a situation in which the U.S. military’s reserve forces would face large-scale mobilization, as they had during the Gulf War. The monthly training weekends were excuses to get away from jobs or college classes, and spend a few days enjoying life in an adventurous culture outside the mainstream.

We were in awe of Marines who’d been to Kosovo, Somalia and Kuwait. In boot camp my senior drill instructor laid out a display of his Gulf War pictures and souvenirs in our barracks as a motivational tool. To see a Marine wearing a Combat Action Ribbon was a rare and thrilling experience.

Conversations about tactics and equipment would often begin with the phrase, “if we go to war,” or “if we get deployed.” Of course, today it’s no longer a matter of “if” but “when.” No matter how hard we trained or how much we learned, at the end of the day reservists could go to sleep knowing the likelihood of combat deployments was a distant one.

One day in 2000 my platoon sergeant half-jokingly said that all of the college kids who enlisted to get some extra cash for school were going to pay it back with some kind of mobilization one day. No one took him seriously at all.

Still, there was a strong desire to someday go to war. We would bid our families goodbye with heroic farewells and prove our fighting potential as generations before us had in other wars. By sunset on September 11, 2001, a new reality slapped us awake from our childish reverie.

In those early days after 9/11, it seemed many of my comrades approached with bewilderment the rapid transition from a peace-time fighting force to a wartime machine. Will I actually have to shoot my rifle at something other than a target? Am I gonna get killed? Am I in shape enough in case I have to hike through Afghanistan’s mountains? How long is this all going to last? Are we at least going to get combat pay?

In January 2002 my battalion was among the first in the Marine Reserve mobilized in direct response to the 9/11 attacks. I considered myself lucky that among the many infantry battalions, mine was chosen to mobilize and serve in what seemed an anxious but historic time. As we traveled to Camp Lejeune, N.C., for a yearlong stateside activation, the attacks permeated our thoughts as the single event that took us from our homes and presented us with an uncertain future.

On the first anniversary of 9/11, training was postponed, and we crowded into the barracks’ recreation room to watch the memorial service at Ground Zero. As a unit comprised mainly of Marines from New York state, many of us had tears in our eyes as the names of friends and acquaintances were read aloud on TV.

When I deployed to Iraq six months later, the memory of 9/11 was foremost in the minds of some Marines, and totally absent in the minds of others. One friend said the 9/11 attacks were the beginning of a long journey he was set upon as he served his country. As a New York-based unit, our Humvees were marked with a small rendition of the New York City skyline, the World Trade Center towers still rising tall.

For others, the immediacy of our situation seemed to trump any time for day-to-day reflection of what ultimately had sent us to war. I remember one fellow Marine sarcastically saying that he only thought about 9/11 twice a day–once at 9:11 a.m., and once at 9:11 p.m.

After I returned from Iraq I don’t recall ever hearing 9/11 mentioned as often as it once was. That’s not to say no one thought about it. But the common discourse was of the current war at hand.

Rumors that once centered around where the two-week Reserve training sessions would be held were replaced by rumors of when the next activation would take place. Reserve units were broken up as many Marines volunteered to leave their home units and augment another about to deploy. Ammunition for training was limited, because most of it was being sent to Iraq. Training procedures were changed in reaction to reports of lessons learned from soldiers operating at the front.

The names of Marines who’d stood in formation with us on Friday nights for the start of a drill weekend became the names of hometown streets memorializing their deaths in Iraq.

Despite two activations, I still find it incredible that world events could impact the daily life of my own Reserve rifle company of roughly 140 Marines. This was the place I’d stepped into in 1999 as a 19-year-old fresh out of boot camp, simply worried about impressing my superiors and fitting in. When I left in 2005 there were rumors the unit would be mobilized again for another Iraq deployment. They were, later that year.

This is how it continues on the sixth anniversary of the September 11 attacks. I’m now used to living during wartime and seeing Marines leave for uncertain futures in a combat zone. Because 9/11 was never spoken about among my comrades, I’d always figured it was a memory made distant by time, and all that happened in our military lives since that day.

Then last night I received a text message from a Marine friend who’d served with me throughout both our activations. “9/11 tomorrow fellas,” it read. “Just wanted you all to know I think of you often. Semper Fi.”