Marx studied and accumulated Hegel's philosophy for many years before he became a well-informed person.
Wang Xizhi traveled the vast rivers and mountains, watched Gongsun dance the sword, and had an epiphany, which greatly improved his calligraphy!
Kuang Heng of the Han Dynasty stole the wall and light, and studied hard. Later, when he had no books to read, he went to the rich man's house to work for free, but as long as he read books, he eventually became a scholar. Su Qin. So is Zhang Yi!