Richard Roberts wrote:

The UK government have (half-heartedly) been trying to remove old units
of measurement for about as long, and that's not going too well.
Arguably, non-metric units haven't been in full use for 30 years, and
people of all ages are still familiar with them.

And then there are things that are priced by weight and sold by unit... I was in
a Devon Tesco this past summer at the deli counter and wanted to purchase a
small amount of sliced ham. In the US I'd ask for a 1/4 pound. The price tag on
the ham listed the price in metric units and then helpfully listed the
equivilent price in imperial weight. I asked for about 100 grams. The clerk
responded, "so you want 3 or 4 slices then?"