20几岁最该学也最难学的东西

What are the most difficult and useful things people have to learn in their 20s？

二十几岁的人最该学也最难学的是什么？

获得10.1k好评的回答@Brandon Chu

These are the most difficult things I've learnt/am still learning.

这些是我已经学会的、还在学的最难的事情。