In certain industries, “M” connotes a thousand, and “MM” connotes a million. I understood what the poster was saying, it was not dumb. Your reply was.
Taking our language back one definition at a time. One more way to resist the metric system.
During WW2, the US often indicted the amount of a contract by using “M” for thousands. Don’t know why but I just copied a bunch of them for a case I’m working on.
And they say on a list of such contracts that “M” stands for “thousands” and uses the word “Millions” as itself.