Playing between the keys ...

In the early 1990's, Chevrolet leased a Corolla design from Toyota and used it to build a Chevy Nova. I drove that car, and the only remarkable thing about it was that the radio had four preset buttons. That meant I could quickly tune four FM and four AM stations, a pretty small set.
Driving to work one day I accidentally pressed two buttons at once, my finger falling between them. The radio responded by tuning a frequency I was unfamiliar with. Later that day I tried to figure out what had happened and made an amazing discovery: I had SEVEN presets for each of AM and FM! Holding down any pair of contiguous buttons acted like a separate button. I happily made presets for my seven most favorite FM stations.

Now at that time I was managing a group of psychologists at a computer company who did Ergonomics to help plan new products, and wrote user documentation to try to explain to the customers what the developers had insisted on developing anyway. The psychologists and programmers had a rather contentious relationship. So I could just imagine the radio programmer talking to the person writing the car manual:
"I implemented this neat thing! There are only four buttons, but there are seven presets because you can press two buttons at once."
"What?"
"Like, you press buttons one and two together, that's a separate preset. It's terrific!"
"Okay I get it. I'm not going to write it up in the manual, it'll only confuse the car owners."
"But I ADDED VALUE!"
"Car owners like a car manual to be very simple. Trust me, most people who buy a Chevy Nova wouldn't understand anyway."