медведь на ухо наступил (medved' na ukho nastupil)

Literally: A bear stepped on one's ear

Example: “Я люблю петь, но мне медведь на ухо наступил.” — I love singing, but I'm completely tone-deaf.

English equivalent: To be tone-deaf

Origin: No single confirmed source survives, and several explanations are offered. One reads it as a straightforward reflection of the bear's traditional Russian reputation for clumsiness, dim-wittedness, and sheer physical bulk — the largest, least graceful animal in the forest being a natural stand-in for something crude enough to ruin a delicate sense. A second, more speculative theory reaches for actual bear hunting, where close encounters with the animal genuinely could and did leave hunters injured, including around the head and ears. A third simply treats the phrase as pure hyperbole: if the forest's heaviest, clumsiest animal genuinely stepped on your ear, no musical sensitivity could plausibly survive the encounter. A closely related version substitutes an elephant for the bear, built on the identical logic of an enormous animal's foot ruining a small, delicate sense.