Question

It is foolishness to believe that you can be whatever you want to be especially if someone else has the same dream

Answer 1

It is not foolishness to believe that you can be whatever you want.

Every person is a unique individual with a different background and upbringing and thus this means you have different goals and aspirations. People's goals and aspirations can be similar or the same but just because two things are the same doesn't cancel them out.

Having realistic expectations are important when having goals and aspirations because naturally, you cannot become a unicorn or own the world.