After prying my car door open this morning (almost literally), my car told me it was 20F out. Wow. It's not that that's really special in itself, even though it's pretty unusual in Seattle for temperatures to dip that low, but the fact that struck me is that the display on my car didn't have the snowflake icon it usually does when it gets cold.
As I was driving in to work I hit a spot that was slightly warmer and the icon came up at 23F. I know it comes on at the top range of 41F. Maybe it's just the way a programmer thinks but someone somewhere made a decision to write some code that only shows the snowflake between 23F and 41F. Those things don't just happen by magic - there's a lookup table or a function or something that drives it.
Did someone decide that 22F was cold enough that people should know it's cold and icy outside? Why not 24F? Why not program it so that it always shows if it's just colder than 41F? There's so much thought that goes into these little things it amazes me. And I can imagine the rounds of requirements gathering that brought us that decision, and it baffle me.