【若存若亡】〖ruò cún ruò wáng〗[vague]

若巧合符节，

存心牢记着。

若即却躲闪，

亡逸难捉摸。

有时记在心里，有时则忘记掉。形容若有若无，难以捉摸。Sometimes note in in my heart, sometimes be forget drop it. Describe is if have if no, difficult to fathom. 同：若有若无。