Consider learning to play the piano. Almost everybody thinks about doing so at some point in their lives. Most who give it a try, find the bench becomes very hard in a very short time, particularly when practicing scales. Few stick it out to the point of being able to play popular songs. Even fewer achieve the skills that enable them to perform publicly.
Great pianists are rare.
The path to a success in business is not unlike the one leading to success in any field. It is blocked in many places by hurdles tougher to deal with than a piano bench. And while many manage to learn enough to build a business that supports them, few become millionaires. And billionaires are scarcer still. Think back briefly to your school days.