「いつかのオレ」になるかは、今日をどう生きたかによる。(“Itsuka no ore” ni naru ka wa, kyō wo dō ikita ka ni yoru.) / Whether you become “your future self” depends on how you live today.

日本語 / Japanese:

人生は「いつかはオレは・・・」と思いつつ、それを果たすことなく、いつしか終わるものだ。(Jinsei wa "itsuka wa ore wa…" to omoitsutsu, sore wo hatasu koto naku, itsushika owaru mono da.)

「いつかのオレ」になるかは、今日をどう生きたかによる。("Itsuka no ore" ni naru ka wa, kyō wo dō ikita ka ni yoru.)

単純だが厳しい現実だ。(Tanjun da ga kibishii genjitsu da.)

English Translation:

Life is spent thinking "Someday I'll become someone," yet many people reach the end without ever becoming that person.

Whether you become "your future self" depends on how you live today.

It sounds simple, but it's a harsh truth.