Doctors have stories about cures they didn't think would work that did. Writers experiment with the narrative craft. Artists and architects have tons of examples of creative people taking unique approaches to difficult problems.
I'd like to hear about what systems you've built yourself, seen, or heard about that solved an important problem in a simple, unique, or elegant way that took you a long while to arrive at or understand.
Mine was when a colleague calculated tomorrow's date with a simple yyyymmdd+1. Checked in Friday before leaving the office, thus the product feature shipped on time. Of course failed on the last day of the month but by then all the launch celebrations were done and it was treated as a small bug. I think he did the right thing on the day, just should've wrote the issue down and fix it quietly the following days.