Isn't the "go up by a factor of ten" pattern you describe more of your parents spending behaviors (until you are old enough to get odd jobs by yourself) than an

Isn't the "go up by a factor of ten" pattern you describe more of your parents spending behaviors (until you are old enough to get odd jobs by yourself) than anything else? The concept of "save money and put your loose change coins into a piggy bank" could be much older than how much disposable income kids[1] today have. My hypothesis: Maybe the intended lesson was more coherent with the reality a century ago. Here is the first graph I found with a search engine of USD purchasing power: https://www.statista.com/statistics/1032048/value-us-dollar-since-1640/ https://www.statista.com/statistics/1032048/value-us-dollar-... . After the Napoleonic wars until WW2 or so the purchasing power of 1 U.S. dollar spend most of its time increasing followed by sudden drastic drops in value during ... the Civil War and WW1. [1] Or a random HN user got as a kid.