It was like talking to a brick wall. A very dumb brick wall that couldn't get it through their head that the units didn't matter, and that what mattered was the ratio.
I feel your pain. The tough part is realising how pointless those "someone is wrong on the internet"[1] discussions are. I get embarrassed looking back at situations like that, and think "why did I even care if this random person didn't get what I was saying about <thing-we-were-arguing-about>?"
Oh, I agree. I was as dumb as him for participating in it. If I'd any sense, I'd never have engaged with him after it became clear that he was fixated on something completely separate from the actual point.
Exactly! Furthermore: In that case, it gets more vexing the longer it takes you to arrive at that conclusion.
When it's the other way round, you can find peace at some point (even if it takes months or years). But if you were the brick wall, it first takes months or years and THEN, when you finally do realize the reality of the situation, it takes even longer to settle. shudders
The A0 being 1m^2 is important because paper weight is given in gsm - grams per square metre.
Thus when calculating postage weight by counting the number of sheets you can calculate that, for example, the weight of one A4 sheet is 1/16 the gsm of the paper - 1/(2^4).
In order to figure out the actual mass of a sheet of U.S. paper from the reported basis weight, you must know how many sheets of paper were in the "basis ream" and what dimensions they were. The basis ream sheet dimensions may have nothing to do with your final sheet of paper, and the number of sheets varies too.
