First, you need wisdom. Mathematics is really a game played by smart people. Don't say that you can make it up without hard work. This does not apply to mathematics.
The second is skill. You need to keep doing problems to supplement your skill training, which will help you better understand the knowledge.
The third and most important point (insight) is that an excellent mathematician needs profound insight in order to stimulate his creativity.
What people lack most is this, which needs to be accumulated, but more importantly, the feeling of mathematics. I believe that the feeling of numbers exists, just like Euler.
Galois, Ramanukin, Gauss and so on, their experiences all illustrate the importance of number sense.
I always think that mathematicians are only excellent and great, because people who can be called mathematicians are excellent in their fields after all, but those who can be called great are Gauss, Poincare, Hilbert and others, who have established a series of theories themselves and formed a branch of mathematics.
There are many excellent mathematicians in China, but few are great. Qiu Chengtong, who won the Fields Medal, is not great, but Chen Shengshen is great.