My freshman year in high school in Illinois, I was sitting in the hallway, reading, when a girl who'd been in my 3rd grade class in Montana walked by and recognized me. Our Dads were both in the Air Force and their careers had brought them to the same bases.
When I was a senior in high school, in Maine after my Dad retired, I worked at a Burger King. One of my coworkers (a REALLY, REALLY hot Asian chick) was dating a football player from our rival school. I met him just a few times when he'd come see her. I enlisted right after graduation and got stationed in Germany. One night, I was in a bar making out with this freaky chick I'd just met when this dude walked up to me and addressed me by my name, basically telling me to get a room. I looked up and realized it was the guy who'd dated my former coworker. A few weeks later, my company took an orientation flight on some UH-60's, during which one of my battle buddies puked all over himself, the rucksack he was holding in his lap, and the floor of the bird. When I told my former coworker's ex, who was a Blackhawk mechanic, he told me that it was his bird and he'd had to clean my buddy's vomit out of it.
About 8 years after I left Germany, after a 5 year break in service and a change in MOS's, I was in the map warehouse at Fort Campbell when this Specialist walked up and asked me how I'd been. It turned out, we had been in the same unit in Germany and he recognized me, though I couldn't recall him.
About a year after that, I was walking into the Ft. Campbell clothing sales store, and, as I walked past the shoe/boot sales area, recognized my former team leader / track commander from the second unit to which I'd been assigned in Germany.
A couple years ago, thanks to a post I'd made here about the unit I'd been assigned to in Germany, I got an IM from someone asking about when I was there. It turned out to be one of the M-60 gunners from another platoon, who I used to hang out with from time to time. When we got to catching up, we realized we now live about 30 miles apart.
I was in a local hardware/home improvement store, wearing a hat with my former unit's regimental crest on the front. A guy in line behind me asked me when I was with the unit. I told him and we got to talking. He'd been assigned to the same brigade years before me, but was later assigned to the company from another 101st ABN brigade which relieved the one I was in at the end of our Kosovo deployment. We had spent about a week on the same little firebase 14 years before as we turned over our Area of Operations to his unit. (When I say small firebase, I mean tiny. It barely held four GP medium and one GP small tents, along with a small area for us to park our Humvees. It had about enough room for 40-50 people to live, and that was about it.)
If there's one truth about the military, it is that it makes the world very small.