The expression "cut yourself on the nose" is used in those cases when they want the interlocutor to remember something for a long time. And the prominent part of the face has nothing to do with it.
Commemorative plaque
In ancient times, the peasants did not know either literacy or counting. And if one asked the other to borrow several sacks of grain or flour, they could not make notes or draw up receipts. And so that no controversy arose during the settlement, the borrower brought with him a long wooden plank, which was called the "nose."
On this board, transverse notches were made according to the number of borrowed bags, then the board was split from top to bottom, and each remained a half with notches. When the debtor came to return the bags, both parties to the transaction put their halves of the nose together. If the notches coincided, and the number of sacks was equal to the number of notches, this meant that none of the peasants had forgotten or confused anything.
The same custom existed in medieval Europe. In the Czech Republic, for example, in the 15-16 centuries. innkeepers widely used special sticks - "cuttings", on which they applied, "cut down" with a knife marks on the amount of drinks or eaten by visitors.
Homonymy
The word "nose" in the expression "cut your nose" does not mean the organ of smell at all. Oddly enough, it means "plaque", "tag for notes." The name of the plaque itself obviously comes from the Old Slavonic verb "carry" - in order to be useful from the notches, this plaque always had to be carried with you. And when it is desirable not to forget or confuse anything, and they say: "Cut it on your nose!"
In addition, the word "nose" was previously used in the meaning of an offering, a bribe, and if someone could not agree with the person to whom this nose was intended, this unfortunate someone, as you might guess, stayed with this very nose.
Thus, the phraseologism "cut yourself on the nose" lives on to this day, and its original meaning has lost its meaning.
Interest of scientists
Of particular interest to etymologists is the relationship of the alleged homonyms nose "olfactory organ" and nose "tag with notches for memory." Trying to completely reject the association with the first homonym as absurd, E. A. Vartanyan notes that such an understanding would testify to cruelty: “It’s not very pleasant if you are asked to make nicks on your own face,” and, calming readers from this “unnecessary fear,” proceeds to an exposition of traditional etymology.
In a slightly different way, without denying the completely natural in everyday perception of the associative connection of the turn “to hack to death” with the nose as “the organ of smell”, V. I. Koval. He includes material from the Belarusian, Ukrainian and Bulgarian languages in his analysis. Recognizing the original meaning of "tag for records", he emphasizes that gradually this word began to correlate with the well-known meaning, which led to the loss of the original image. Due to this, a person supposedly perceives it as "an image of a notch on the nose (the organ of smell)."
