Choosing a career that match your ability
Sometimes interest alone is not a strong enough factor for a career decision. You must also look at your ability because sometimes what you like is not necessarily what you are good at. I have interest in football and I like watching football games, but I simply do not have the athletic ability to play at professional league and therefore, a career as a professional footballer is out of the question for me.
Choosing a career that match your motivation
According to Abraham Maslow, human needs have the following hierarchical order: physiological needs, safety needs, social needs, esteem needs, cognitive needs, esthetic needs and self-actualization needs. Although some scholars argued against the hierarchical structure of these needs, I believe that each person has his own unique levels of needs. So examine yourself and try to figure out, for each category of needs, what level you find acceptable and then see how the career you choose can fulfill the needs.