I've learned almost all the slurs I know from comments or media sources complaining about them. It's the only place they're used in polite society.

It isn't really a surprise in this case since both ethnic Mongolians and those with Downs syndrome are not in many Americans' social circles.

"Almost all" does sound like a bit of a surprise, but thinking back on it the only one I know for a fact I heard for the first time outside of a corrective context was my elder uncles friends who enjoyed self-depreciating jokes, usually with slurs for eastern Europeans in them. I first heard those as a child and only realized years later they were offensive. Most others, I think, I honestly have no idea when i was first exposed to them.

Mongo and mongol don't have a close relationship: the final syllable is entirely different.

It's implied that someone is going around calling people with Down's syndrome "Mongos." "Mongol" is an actual non-offensive[0] word which means, unsurprisingly, someone who can trace their lineage back to the area around Mongolia.

[0] https://en.wikipedia.org/wiki/Mongols (If it's used descriptively on Wikipedia, it's probably not considered offensive.)

Mongol is not (as far as I am aware) an offensive word. Mongoloid[0] (which "mongo" is a shortened form of) in reference to people with Down Syndrome, definitely is.

My pet theory is that the database is named after a character in "Blazing Saddles", and I want to be able to store candy in it.

[0] https://en.wikipedia.org/wiki/Down_syndrome#Name

This says more about you than the baseline.

Then perhaps count yourself lucky to not have had some of these used against you.

I always thought it was a reference to valuable stuff picked from trash, which I understood to be slang from sanitation workers, but apparently that's local to the NYC area.