Old thought: I once handed someone an example function that was basically `rand() -> 4.` (thanks, xkcd) and that made its way into production. Later, because we always had that value of 4, we'd end up with collisions during high-traffic time windows. I was a little surprised by this, but my take-away is straight forward: don't use joke examples. Folks will use them, and you'll only find out later. It only works if you're both aware of the joke – something you can't assume. Just don't do it.
Actually fixing this wasn't very interesting, by the way. It stood out in the code after we dug through it. It only showed up much later, which was the unfortunate thing. I forget why code review didn't catch it on the team that wrote it, but we were pretty much in crunch the entire time. It's very likely that things got glossed over, or reviews were skipped entirely.
Correction on phrasing: Maybe you'd think they know something you don't and you implement exactly that.
Writing is hard and my brain inverted actors in this. I think the point gets across, but correction nonetheless.
A single-user instance for Noel Cower.