What to learn depends on this person's hobbies. If he doesn't like math and has to learn something he doesn't like because he has to go to school, but he can't learn it, then he will have negative emotions. This theory of uselessness comes from the statement that he has learned so much that he doesn't know where he is going or where he might go. There are many students who are partial to the subject! He even learns what he likes faster than the teacher teaches him, and he can understand many people who fail in the exam, but the perfect score is like this. He won't care about anything unless he likes it. There is no science without mathematics, which has nothing to do with him.