An idiom meaning that giving something valuable (or good advice) to someone who cannot appreciate it is wasted effort (cf. "casting pearls before swine").
高級ワインの味を説明しても、彼には豚に真珠だ。
Explaining the taste of fine wine to him is like casting pearls before swine.
専門的な法律用語で助言しても、一般の人には豚に真珠かもしれない。
Giving advice in technical legal terms might be wasted on an ordinary person.
子どもに難しい詩集を渡すのは、時に豚に真珠だ。
Handing a difficult poetry collection to a child is sometimes casting pearls before swine.