Some calamity wipes out most of humanity and hundreds of years later, historians are puzzled by the funny McDonald’s marquee message some kid arranged as he was flipping off his manager.
A finch is is a unit I made up in my head to make sense of the weird customary system. It’s 4 inch (four inch -> finch) or rather 10 cm. Makes converting my instinctive scale to USian easier. It helps, that it’s also a plausible size of the finch bird.