When my daughter and niece were 11 and 9, we had a paper airplane folding afternoon. We went through the handful of designs I remembered from middle school with some level of success. All along, I was teasing them about a super plane I knew how to make.I eventually made it and it flew so much better than all the other ones… but they hated me for it.

It turned out that they wanted paper planes that conformed to their idea of a paper plane, not paper-based engineering marvels.

Apparently, that design is called "two loops".

I’ve pulled that trick multiple times, normally successfully; some people appreciate such shenanigans.

A similar anecdote. There was once a bridge-building competition, with provided materials, and scores for it bearing different weight toy cars, for height and for length. Nowhere was it said the bridge had to bear any of the cars. Our group’s 15-metre long roll of tape bridge with four-pop-stick-A-frame supports, which scored three times as much as the next (… and we could have doubled its length), was unceremoniously disqualified for unspecified grounds, as I had expected. I pressed for a few days for the grounds (even suggesting the couple of not-unreasonable grounds I had thought of, such as that our team had schismed into two over the creative direction), but was not given them.

The unwritten rules about spirit can be applied capriciously.

I think ours was still the most popular bridge. And honestly one of the more realistic, just scaled for much smaller vehicles, a consistent 1:500 where most were an inconsistent 1:25 to 1:50. They were really good supports.