Could that be a UK thing? I wouldn't know tbh, because between mixing yards and miles versus sticking to imperial units in the 21st century, the latter is definitely crazier ;)
Yep, we mix them up. Distance and speed in miles, fuel priced in pounds per litre.
In Canada we have imperial for short measurements (inches and feet for lumber, people's heights) but metric for longer distances (kilometers for driving distances for example)