Reading via mastodon translate a thread by a French poster about recent actions by Macron and partway through got slapped in the face with the discovery that "I'll eat my hat" is an idiom in France as well as America ("Bon, je mange mon chapeau, et c'est pas très bon.")
Is this… how universal is this? Do they eat hats in Germany? Russia? What percentage of earth has a local-language idiom for eating hats?

Census from responses:

Eat hats: English, French, Norwegian, Swedish, Danish*, Icelandic, Hungarian, Finnish, Estonian*, Hebrew

Do not eat hats: German, Russian, Spanish, Italian, Polish, Yiddish, Mandarin Chinese

Contradictory data re: hat-eating: Dutch

* Hat may optionally be "old"

Provisional unified theory of hat-eating (highlighted countries eat hats to express an unlikely event has occured)

The major outstanding question here is whether they eat hats in Estonia*. Is this a universal feature of Uralic languages

* Update: YES

I was supposed to be doing my taxes this morning

It can be dangerous to draw inferences from raw decontextualized data but at this moment, with data from Norway now incorporated, it certainly seems plausible that Scandinavia was ground zero for hat-eating and the trend spread along language affinities from there

Now, you may ask: But then why did hat-eating not catch on among the West Germanic language group? One tentative explanation jumps immediately to mind

@mcc In Germany it's "Ich fresse einen Besen!", to "I eat a broom!"
(sidenote: "eat" has two translations, "essen" and "fressen", and "fressen" is mostly used for animals)