BlueBelle, don’t label yourself stupid.
Adults who’ve only ever worked in metric never had to learn and would have to work hard to cope, with ounces, pounds, stones, quarters and cwt, or inches, feet, yards, chains, furlongs and all the multiplication tables that went with them.
They missed the joys of knowing that there were 240p 480 1/2p, 960 farthings in £1 (with an extra line on the £ sign.)
I’ve heard children grumble about being asked to calculate how many cm in 3km. Sadly they missed out on calculating 63,360 inches in 1 mile so how many in 3 miles.
We’re definitely not stupid!