I loved this example of the kind of legacy thinking that goes unquestioned for years (originally via). The standard size of wine bottles was formalised around the world for the 1973 vintage at 750ml. US sizes until that point had been a half gallon and a gallon but 750ml had been the default size for standard wine bottles in many parts of the world for centuries.
Why that size? Well, in the 16th and 17th centuries wine bottles were made by glass blowers and 750ml was the typical lung capacity that a blower could use to create one bottle with one breath. Amazing isn’t it, a standard that was set hundreds of years ago based on an old way of working that has survived unchallenged ever since. I’m sure there’s hundreds more (I’d love to know if you have one), but this is a classic example of what I once called a toxic assumption – the kind of (often hidden) assumptions which so often go unchallenged within businesses but which can be a barrier to innovation and different thinking.