expression, noun
pearls before swine; unused treasure; wasted potential
Idiomatic expression for a valuable thing or talent that is not being used effectively, often because the owner cannot appreciate or utilize it. Similar to the English 'pearls before swine' but also used for personal abilities or possessions that go to waste.
彼に高級ワインをあげても宝の持ち腐れだ。
Giving him expensive wine would be like casting pearls before swine.
せっかくの才能を使わないのは宝の持ち腐れだ。
Not using your talent is a waste of potential.