You may want to do something and other people tell you “No, you can't, etc”. What do you do?
If you really want it, only think of what you want to do?
If you don't and listen to other people, you will end up like them, where they are and what they tell you. Your thinking will be shaped by what other people are thinking.
Remember: “I think what I want”, it is so important if you want to live your own life, even if other people tell you otherwise.