What truly can influence investors,

It's not that he learned any methods,
But rather what kind of thinking he learned.
A person's way of thinking determines his entire life. Thinking logic is not knowledge, nor does it produce knowledge, but it determines how a person applies what he has learned and how he processes the information he receives. Most people learn similar knowledge, but the different ways each person uses knowledge and processes information determine the differences in their lives. Investment is the same; thinking logic is the most important key factor that constrains investment returns.
This is why the news everyone sees, the information they hear, and the price fluctuations they observe are the same; some people make money while others lose money.
Logical thinking is the first cornerstone for a person to gain investment returns.