人情世故

He felt people were contemptuous of his lack of sophistication.

他觉得不起他不懂情世故。

She is unschooled in the way of the world.

她不懂情世故；她丝毫不懂世态炎凉。

He's very young and inexperienced, and doesn't know about the ways of the world.

他还年轻, 又缺乏经验, 不懂得情世故。