I live in the US and can't change my thermostat, so I don't think that's it.
I'm sure I could feel the difference if i split myself between two rooms with one degree difference. I just don't think this is a useful granularity—I typically move the thermostat by 2-5 degrees at a time.
I wonder if using a lower resolution scale dulls the senses like other forms of https://en.wikipedia.org/wiki/Linguistic_relativity