I enjoyed reading this exchange, it's really a matter of perspective.

For someone like me living in a country with the metric system there's no issues with negative values for the temperature. It just mean it's below freezing, which is cold, the more below freezing it is, the colder it is. And inversely the more above freezing it is, the hotter it is. For me 20C feels good, 30C is too hot, 40C is at the point where I can't work anymore, and anything above that doesn't exist around here. 100C is where water is boiling at sea level. Easy.

Another thing that's interesting to me is that going from 300m to 0.3km is automatic, it maps to exactly the same concept to me in my mind, I don't feel like I'm doing any conversion at all and one is not harder to use than the other.