it's just one of those things

said about an event or situation that you cannot explain, or do not like but cannot change

(表示无法解释或不喜欢，但不能改变的事)这是难免的事

The road was blocked, so we missed the meeting - it was just one of those things.

路被堵住了，所以我们错过了会议——这也没办法。

Getting sick is just one of those things, Mom. Don't worry about it!

谁都免不了会生病，妈妈。别担心!