Everyone served with that grumpy, old, gray-haired specialist or buck sergeant who had already lived a full life as a civilian by the time the Twin Towers came down and he enlisted. His age, experience, and willingness to openly criticize arcane military procedure were just plain annoying to many of his peers and junior leaders. But give “gramps” his due. He was happier to serve with you than he let on. At least I was. As a 41-year-old enlistee who deployed twice with the 82nd Airborne Division, here’s what I came to understand.