How not to think of career:
“I’m going to university to become a biologist.”
“I am a biologist. I’m going to university to get further practical knowledge and certification.”
The point here is that one should start being a biologist a significant amount of time before deciding to go to a university (say) to further one’s biology-related career. That is, one should start doing things that biologists do before deciding to go to a university to further one’s career in this area.
Most high-school students ‘decide’ to start a profession without having done much of anything in relation to that profession! Most of the time, they don’t actually have good reasons for believing that is the right profession for them.
This attitude is part of the institutionalization (‘Mandarinization’, to use William James’ phrase) of Western society, education, and careers.