How to treat more and more elderly people looking for jobs after retirement?

The biggest gap people encounter after retirement is mental and physical changes:

I feel empty and idle. I don't have the vigorous and colorful life when I used to work, as if I had been abandoned after leaving society.

I feel very relaxed physically, and all kinds of minor problems will come out, and my health is getting worse and worse.

The best way to solve the above two problems is to do something you can after retirement, even if you are engaged in some knowledge sharing and hobbies that you are good at in your previous job, you can help yourself not to be decadent or empty.