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Katznelson was born in Bobruisk, Russia (now Babruysk, Belarus) on October 25, 1885 (15 Heshvan 5646), the second of the six children of Zelda (née Rozovsky) and Nisan Katznelson.
The biggest hint that the story is a joke, as Hyppönen pointed out, is the name of the city: Bobrujsk, which might just be a differently transliterated version of Babruysk or Babruisk - something like the Russian equivalent of Scunthorpe, in comedy terms.
My late grandfather, who died before my parents met, came from Babruysk before the First World War, managed to get a place at University despite his lack of English, and started a Yiddish newspaper himself.