Metric Rules or Does it Really?

I worked through school when there were 20 shillings in pound, 12 pennies in a shilling and thereby 240 pennies made a pound. Within that structure we also had farthings, 4 to a penny. half pennies, threepenny bits, sixpenny bits, half crowns and so on. Was it complicated? Not really. I found it quite simple. Eventually we went to the metric and that ended confusion for foreign visitors from other continents and united us with Europe.
Another obstacle to mainland Europe was the non metric imperial system of measuring. Dead simple system of dividing an inch by any number you want and then subdividing those by halves and quarters hence half inches, quarter inches, eighths, sixteenths, thirty-seconds, sixty fourths and so on. To some, it didn’t make any cents. Oops! I mean sense.
On eBay last week was a three foot fourfold rule made by Rabone Chesterman when Made in England meant something. This ruler was divided up on one side in 16ths and on the other side in 10ths. The seller advertised it as both an imperial and metric. Not deceptive but more a lack of knowledge of the facts I suppose. I paid £8 for my scarcity because no one wants imperial measurements, but the rule mirrored one I bought as a young aspiring joiner, replete with red seals still in tact and in place. I have several Rabone Rulers I’ve collected over the years and i use them at the bench for some work. When I was a boy men wore none fashion men’s workwear usually bought as bib and brace overalls that slipped over our general clothing such as jeans. In and along the right leg starting at from bend of the knee and down was a long ruler pocket that took the 9” length of the folded rule. No one I knew used a tape measure back then. My original rule is still current for me. When I was in school we were imperial, Metric invaded in the late 60’s and we converted to longer fourfolds that were ungainly and awkward. I migrated to the US in 1987 and was shocked to find feet and inches back in my life. I converted back to that. IN 1999 I returned to the UK to start New Legacy UK and switched back to metric to find half of the UK population did, like me, understand and indeed work in both unit types. Anyone under say 40 didn’t generally work outside of metric.