This is a metaphor. unlike a simile, for example, Brave as a fox comma it does not use like or as. the definition of a metaphor is, a figure of speech in which a word or phrase is applied to an object or action to which it is not literally applicable
The idea of what it means to be successful after high school greatly varies from person to person, as everyone has different goals and aspirations for their future. In today's society, being called successful is often associated with wealth, however for many this is not the goal.
Many people strive to be morally successful over wealth, as they feel that being part of a good cause is more important. Many professions that fall under this category are joining the army to protect and serve, representing your country in international sports, or participating in a non-profit organization.