Remavas

Because Joule is the SI unit of energy, meanwhile the Watt is the SI unit of power, equivalent to one Joule per second.

“Converting” joules to watts would be like converting m/s to US dollars.

I don’t see how your example is ‘funny’. That’s what you expect to get. -5² is -25. (-5)² = 25.

Glad I can count my own country, Lithuania, among the enlightened.

EDIT: Source of the picture: https://en.m.wikipedia.org/wiki/File:Date_format_by_country_NEW.svg