All work and no play makes Jack a dull boy.

Definition: Idiom means that you need to have fun in order to be a happy, healthy person
这句话就是传说中的“只工作不玩耍，聪明的孩子也变傻”。例句：

Go home! Remember: All work and no play makes Jack a dull boy.
快回家吧，要记住：只工作不玩耍，聪明的孩子也变傻。

I'm worried about him. He hasn't yet understood that all work and no play makes Jack a dull boy.
我很担心他，他还没有明白过来，只工作不玩耍，聪明的孩子也变傻。