宝たからの山やまに入いりながら手てを空むなしくして帰かえる

expression

to let a golden opportunity slip away; to come home empty-handed from a treasure mountain

Proverbial expression for squandering a rare chance or failing to capitalize on a favorable situation. Often used as a cautionary remark.

• せっかく留りゅう学がくできたのに、遊あそんでばかりで宝たからの山やまに入いりながら手てを空むなしくして帰かえるようなものだ。

  Even though you had the chance to study abroad, if you just fool around, it's like entering a treasure mountain and coming back empty-handed.

• 彼かれは有ゆう名めいな研けん究きゅう者しゃの下もとで学まなんだが、何なにも身みにつけず、宝たからの山やまに入いりながら手てを空むなしくして帰かえった。

  He studied under a famous researcher but learned nothing, like entering a treasure mountain and returning empty-handed.