I'm starting to hear people talk in km but nothing official

We use lb and stone at home for weight but medical its kg

Personally I was taught in the 80s and early 90s they trued to teach us both metric and imperial. I also did an apprenticeship in metric on imperial lathes and mills

I have no clue how less than an inch works past 40, thou being 1mm I struggle with my weight in kg. Miles might as well be a unit of time as beyond telling you how long it takes to get somewhere miles are useless

Bonus anecdot

When I moved out of my parents I had to ask for help buying minced beef because growing up I learned I needed 1/2 lb of minced beef but it was packaged I'm 500 grams