Some of use in India don't even grok inches, miles, pounds, pints, ares or cubits. In fact, I haven't met anyone in the professional fields (science, engineering and medicine) who is comfortable with imperial or any other non-metric systems. Not even our parents are comfortable with them. It was a nightmare when we were faced with such units in public exams. That's an arcane skill that disappeared 3 or 4 generations ago. To be clear, I'm not claiming that the whole of India is like that. But I'm pointing to the fact that there are entire regions in India where it has been like that for generations.