This is the wake-up call for Bing Xin's study. I think a more appropriate understanding is this:
"contented people are always happy": that is, to meet the social needs of things, fame and fortune, that is, contentment is always happy; But as far as human progress is concerned, such as knowledge, things and righteousness, strengthening the country and enriching the people, personal knowledge and career pursuit, we must strive endlessly and never be satisfied.
"Do something and don't do something": do something but not do it, do it for those who should do it, and do it for those who can't; Do not do what you don't do, do what you can, even if you are snobbish.
In this way, the combination of the two warns the world to control the degree and principle in seeking and doing things. The former emphasizes learning while the latter emphasizes doing things.
There is another way to solve the problem of "insufficient content": we should know the advantages and disadvantages of our products, actions, knowledge, thinking, knowledge and language, that is, treat ourselves, treat others, do things and so on. And you should know the shortcomings, if you have enough, you should pay close attention to it, and if you don't, you should make up for it. In this way, it is integrated with the bottom line. The former redoes people and the latter focuses on things.
In fact, it makes more sense to include all these contents. People's life, what they are trying to find, is nothing more than being a man, doing things and learning.