Re: After brexit
Wow, just wow. Cannot believe people would even consider something as catastrophically Luddite and backwards as reversing the use the metric system, (but then I thought that about Brexit).
The world is larger than your shed - standardisation of systems of measurement is essential for the worlds of science and engineering - and safety. (at least one plane crashed because of misunderstanding in whether the fuel requirement was litres or gallons (in this case US gallons)).
I Imagine a British spaceship trying to dock at the International Space Station, but there being a couple of millimetres gap due to insisting on measuring everything in feet and inches and having a Whitworth standard screw thread, leading to the deaths of all on board.
A more down to earth example - Britain post Brexit - our manufacturing industry making Imperial measured parts for the rest of the world (all metric, with the dishonourable exception of the US, who have a different standard even than Imperial). Do we make things that designed to fit with the rest of the world's standards and end up making liquids in containers that are 1.816165874 pints, or do we go it alone and make them in pints and give those foreign chappies no choice but to do the conversions and learn how great Britain is (or, more likely, buy elsewhere).
Standardisation is great for the consumer too - if you're in a shop where there are foreign goods (obviously not something Brexiteers would ever do - they buy only British Wine and Lard, not Olive Oil) - you can compare the prices of two things weighing the same or having the same volume, wherever it's from.