人的思维是有层级的。The way that people think can be ranked in different layers of levels. Smart people will be at the high layer, while less smart people will be at the low layer.

After taking and failing the entrance exams for specialized secondary schools for a few years, some students had to go to an ordinary high school, and after three years of studying, they won the university entrance examination.

This is what I really mean.

You are right. What I want to express is that choosing 3 people from 100 people compared to choosing 10 people from 100 people. that the three people must be better than the 10 people.

Thank you very much.

“People’s opinions can be put into different categories. “
I couldn’t agree more with this saying. Since Fang Zhouzi was mentioned earlier, which led to a heated discussion, I want to say something about him. To be honest, I don't know much about him, but I did watch one of his videos before. I didn't finish watching it because I quickly got my impression of him. I don't think he is a capable person, maybe not even a normal one. I know that his educational background makes it sound like he is really awesome, but I don't think that is true. Are people who have higher education diplomas always better than those who don't? No, that’s definitely not true. I have to admit that oftentimes, I judge people by intuition based on their words and actions, but I think this method works most of the time. At least for me. It's true that Fang has a very good educational background, but why do I think he is not a capable person? In the early 1980s, when students graduated from middle schools, their best choice was to go to a specialized secondary school because if they were qualified to go to a specialized secondary school, that means they had already gained the opportunity to work in the government. The acceptance rate of students in specialized secondary schools was only 3-5 percent. If you couldn't place in the top three in your class, you probably wouldn’t pass the exams. If you were qualified to attend a specialized secondary school but choose not to go, you could go to a provincial key high school instead, but if you couldn't pass the university entrance examination, you still had to go back to your village to be a farmer for the rest of your life. After taking and failing the entrance exams for specialized secondary schools for a few years, some students had to go to an ordinary high school, and some of them finally had the chance to pass the university entrance examination. Ironic? Do you think the people who failed to get into a specialized secondary school but then had the chance to go to a university are more capable than the people who passed the exams and went to specialized secondary schools? Yeah, I know, those university students have a diploma with a higher degree than students from specialized secondary schools.
Someone with a long educational history is more likely to be capable than someone with a short one. People who are in the top 3% are always better than those only in the top 10%. Educational background is like a journey. Although some people are not very talented, they keep going forward until the end, while others who are very talented may give up halfway for various reasons. So having a nice educational background doesn’t necessarily mean a person is more capable than those who don't. Talented people can understand things with only a glance, while not talented people may need many tries before understanding. That is what talent is.

I think I understand what you're trying to say, but I'm not sure if there is an exact English equivalent. Maybe something like, "People's way of thinking have varying levels of maturity," but maybe someone else can give a better alternative.

I'm assuming that "won the university entrance examination" means passing the exams. You can't "win" an exam, so you should use a different word even if my assumption is wrong.

Just as a side note, "exam" is the term most people use when talking about academic/school-related tests. While "examination" can also mean the same, it's more commonly used to refer to things like a medical check-up or a close analysis of a subject, derived from "to examine."

I'd personally reword the sentence as:

The students that took and failed the specialized secondary schools' entrance exams for consecutive years had to go to an ordinary high school, and after three years of studying there, some were able to pass the [reinstated] national university entrance exam.

"Reinstated" is in brackets because I'm not positive if it should be there. Going by the previous sentences, it seems like you might be talking about when 高考 was reinstated, but my knowledge about Chinese history is very limited, so just ignore it if I'm wrong.

Thank you very much.

The Chinese university entrance exam was reinstated in the year 1977 after ten years stopped.
In the early 1980's, the National College Entrance Examination and the High School Entrance Examination both existed. But students who graduated from middle school all wanted to go to a specialized secondary school instead of going to an ordinary high school, because if students were good enough for going to a specialized secondary school, that meant they already got the opportunity to work in the government after three years of studying there, but the acceptance rate for that was very low, just 3-5%. The majority of students couldn't pass the exam.
So, students who didn't have good grades had to go to an ordinary high school, but after three years of studying in a high school, some of them had the chance to pass the National College Entrance Examination. That meant they also got the opportunity to work in the government after three years of learning in universities.