Not so exaggerated. Girls also love to shake. It is a habit formed as a child and caused by psychological reasons. When shaking your feet, the rhythm is fixed and it is easier to calm down. Sometimes when you can't think of a problem, if you can calm down, you can finish it soon. At school, many people have this habit, which has nothing to do with feudal superstition. The tremor of college students is basically the legacy of high school efforts. No problem. If you deliberately change them, you will soon get rid of them, just like crossing your legs.