A college education is essentially a pathway to success in society. It's apart of the mentality that in life the only way to get a good job, good money and a good life is through college. That's why it's so glamourized everywhere, society elevates the idea that someone who goes to college or has finished college is of great value compared to someone who has dropped out.
The stigma that a high school drop out cannot gain success comes from society's thoughts of an individual not being educated well enough to reach a high level of achievement. This is deeply embedded into society with pressure from parents to go to college to get a 'good' job and the culture that someone who has finished college is equal to someone who is successful and thoroughly educated.
So in society I feel that a college education means someone who has ultimately made it (even in the aspect that someone who has dropped out or hasn't gotten a college education can be just as successful)