Ask HN: How did you successfully hack a (non-computer) system to your advantage?

Back in the 1990's I was a volunteer firefighter. I had been working on getting my FF II certification for a while, and planned to pursue my Fire Instructor certification afterwards (FF II was a prerequisite to that). Anyway, the "Instructor Methodology" class and Fire Instructor test was something that wasn't offered very often, and quite often people had to drive a considerable distance to complete it.

As it happened, I was still something like two classes short of having finished my FF II cert, when an Instructor Methodology class showed up on the schedule at our local community college (the CC's were typically the "delivery agency" for fire service training in NC, at least in rural areas). So... I just signed up for it. Took it, finished it, took the Instructor test, and aced it.

And then the guy from the OSFM (Office of the State Fire Marshall) pulled me aside and said "Wait a minute, you just aced the Instructor test, but you're not even a FF II yet. We can't give you your Fire Instructor certification."

I forget the details of the ensuing conversation but it went roughly the way I had anticipated it might - they said they would just "hold" my Instructor certification until I finished my FF II. About two months later I finished the last class for FF II and a few months later I got a package from OSFM - with my FF II and Fire Instructor certificates. :-)

It was a small thing in the grand scheme of things, but it saved me either having to wait as much as another year or two, OR drive halfway across the state, to get that Instructor class and test in.