не моего ума дело

• Не моего <твоего и т.п.> УМА ДЕЛО coll

[NPgen; Invar; subj-compl with быть (subj: это, abstr, or infin), pres only; fixed WO]

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⇒ sth. is beyond s.o.'s ability to understand and/ or does not concern s.o.:

- это не Х-ова ума дело{{}}≈ X doesn't (wouldn't) understand it and it doesn't have anything to do with him anyway;

- [with the focus on s.o.'s inability to understand] X wouldn't understand (it);

- it's over X's head;

- it's out of (beyond) X's depth;

- [with the focus on sth.'s not concerning s.o.] it has nothing to do with X;

- it's none of X's business (concern);

- not for X to know.

     ♦ "А чего же ты слезу сронила?" - допытывалась любознательная старуха. "И чего вам, тётенька, надо? Не вашего ума дело!"(Шолохов 4). "What are you crying about then?" the inquisitive old woman persisted. "Don't bother me, Auntie! You wouldn't understand!" (4a).

     ♦ "И за это получили из артиллерии?.. С бронепоезда?" - "Разумеется". - "Прискороно. Достойно сожаления. Впрочем, это не нашего ума дело" (Пастернак 1). "So they were shelled?...From the armored train?" "Of course." "That's bad. All our sympathy. Still, it's none of our business" (1a).