I joined the Canadian Armed Forces Air Force Reserves when I was 16. I was a bit too young and ended up quitting immediately after basic training because I decided I wanted to go to university and with the unit I was going to join after BMQ, it wasn't practical for me to go to university at the same time for a variety of reasons.

Anyway, the course I was on was the first in the history of the base (they normally didn't hold basic training there) and it was really poorly run (a bunch of the Master Corporals leading the course kept trying to quit). In the fourth week or so they brought in this older guy who was the Canadian equivalent of the Drill Sergeant from Full Metal Jacket (but more politically correct because this was in 2001) and he spent a lot of effort trying to convince us he was crazy and could snap at any minute.

He was really mad one day and has us do drill in an aircraft hangar for a good few hours as punishment. Part of drill involved standing at attention for an hour or so (with occasional stretch breaks). Being 16, I found it very hard to stand with for that long so I started wiggling my toes in my boots to help stave off the discomfort. Of course, the MCpl sees this, darts up to me, gets right up in my face and yells: "I DON'T CARE IF A LITTLE BIRDY LANDS ON YOUR FOREHEAD, PECKS A HOLE IN IT AND STARTS FUCKING IT, DON'T FUCKING MOVE!"

It was so funny to me at the time that let out a loud laugh then spent 100% of my energy trying to hold it in until I was red all over, had tears streaming down my face and was vibrating with suppressed laughter. The MCpl stood there, frozen, glaring at me behind tinted aviators and after awhile I noticed that even he found the situation funny. Since he couldn't keep his tough guy act up when he was on the verge of breaking into a fit of laughter he just stormed out of the hanger half giggling the entire way. Then we all broke down into a laughing fit. I still crack up just thinking about it more than a decade later.