What is the difference between an aptitude and an interest? Why is it beneficial to find a career that uses your aptitudes? What may happen if your job does not require you to use the aptitudes you possess? (Site 1)

These factors change greatly from year to year as your knowledge and experience grows. It is difficult to be interested in something if, for example, you do not understand what it is. A job title such as "marine biologist" or "industrial engineer" does not say much about what that career is like, and so how could someone be truly interested in pursuing either of those careers?