Young people who don't work hard will be sad (if young people don't work hard in time, they will only regret for life when they get old)
What they get on paper is shallow, and they don't know anything about it (the knowledge they get from books is shallow after all, and in the end, they must know the nature of things or things themselves. I always knew that when people died, there was nothing left. Just sad that I didn't see the reunification of the motherland with my own eyes)