In practical terms, one metre is a pace, half a litre is a large drink, which ways about half a kilogram, and all temperatures below -20 celsius and above 35 celsius are unbearable.
Theoretically all major nations except the united states use the metric system. In practice, all nations including the united states use a mixture of the metric system and older units.
American: We don't know how.
Canadian: It's simple. There are 10 millimeters in a centimeter, 10 centimeters in a decimeter, 10 decimeters in a meter...
American: *Brain overheats and explodes*
1 mile is 1760 yards, 1 yard is 3 feet, 1 foot is 12 inches.
The United States government's hopes of switching to the metric system were dashed once they realized it would cost billions of dollars.
Me: Yeah we went 135 miles per hour for about 5 minutes, the cop was gone.
European cousin: Cool?
During a spirited performance of their hit Metrixxx, Orpheus Higginsigginsabottle-Smyth (the EU High Comissioner for Units at the time), jumped onto the stage and began to verbally abuse frontman The Ridiculous Sleeve for what he called his uneuropean propaganda.
The High Comissioner was not heard from until 3 days afterwards, when he emerged, naked and shaking, from a sewage pipe near Cardiff. When asked to recount his ordeal, his only words were "They went metric on my arse".
American: Did you write that on the internet?
Canadian: Of course, stupid American.
American: Why didn't you use that global system of interconnected computer networks that Canadians invented?