Global standard doesn't mean that every person everywhere uses metric. It means that people everywhere can use metric and they know what it means, and that official weights and measures are done in metric. Use whatever glass size you want at the bar, or measure your horses however you wish, but when you get on the road the signs are in km/h.

Plenty of people are "bilingual" with metric and local. Canadians are universally bilingual with metric and imperial. It's not that hard.