Personality characteristics can be inborn or developed by education or experiences. You are most likely to choose a satisfying job if you choose one that fits your personality type.
Suppose you are a very active person. You like outdoor activities. You also like meeting people of different background. You will enjoy a job that allows you to work outdoors or take care of the needs of people, for example, a sales representative or customer service officer. If the same job is assigned to an introvert, he may find it very difficult and be utterly discouraged.