The article is devoted to the axiological analysis of paremiology, formed according to the "formula of the impossible". The appraisal of such phraseological units and proverbs is created on the basis of oxymoron embedded in their figurative semantics. The author considers Russian, German and Ukrainian expressions of this type. On the basis of structural-semantic modeling, a new etymology of expression в огороде бузина, а в Киеве дядька is proposed.