Definition
This idiom is used to warn someone that they will become uninteresting if they work all the time and never take time to relax or enjoy themselves.
劳逸結合，別只工作不娛樂（否則會變得单調乏味）
He's been working non-stop lately, with no time to relax. I think he needs to remember the saying 'all work and no play makes Jack a dull boy.'
他最近一直在不間斷地工作，沒有時間放鬆。我覺得他需要記住這句諺語『只工作不玩耍，聰明孩子也變傻』。
I'm worried you're working so late all the time; you'll become very dull. You need to rest more, remember 'all work and no play makes Jack a dull boy'.
我擔心你總是工作到這麼晚；你會變得非常無趣。你需要多休息，記住『只工作不玩耍，聰明孩子也變傻』。
The company has been so busy with the big project, I think employees need more time to relax. They need to keep in mind that 'all work and no play makes Jack a dull boy'.
公司最近忙於這個大項目，我覺得員工需要更多時間放鬆。他們需要記住『只工作不玩耍，聰明孩子也變傻』。