Is it a fallacy to think, "You can be anything you want to be"?

Here in the United States of America, we have freedoms. Those freedoms allow us to have the opportunity to be whatever we want to be. The question is if we are designed to be whatever we desire to be, and if not, do we own the motivation and resilience to acquire the skills needed to perform the tasks required for that career? There are so many things that go into choosing a career that is right for you. Understand that you, yes you, will evolve and change, thus you must focus on the things that remain stable throughout life when choosing a career. A high school student is not thinking about what it will be like to be married or have kids, or if they will have to move in a few years to help out his/her parents. The career you choose must be something you are engaged in and motivated to do daily. Also, it must be a career you are designed to do. If you are happy in your career and environmental factors have to change due to family, sickness, kids, etc., it will likely be easier to adapt your career to your new environment. If you are good (no great) at your career and are engaged to know the ins and outs of your tasks needed to perform your position, you are more likely to adapt if changes take place (Hartung & Cadaret, 2017). You can be whatever you want to be, but why climb a mountain when you can go with the flow and easily sail down?