In the same vein, In the mid 1980s I was SDO at Cranwell and thus had to sleep at York House Mess - not my usual. As I walked in a noted a visiting truckie nav who looked familiar. As you do, we went through our service careers trying to match up. Stations? IOT? OCC? .... Finally, having exhausted that we went even further back: We had sung in the same performance of Pirates of Penzance at University about 15+ years before!
Yep, small world!