ˋshìㄍㄨㄛˋguòㄐㄧㄥˋjìngㄑㄧㄢqiān

  1. 事情過了環境改變繡球·》:如此繡球通理事過境遷不在心上。」即景生情記憶猶新

The issue is in the past, and the situation has changed (idiom)​., It is water under the bridge.
(expr. idiom.)​ de l'eau a coulé sous les ponts