The biggest difference I always see is that people who are well into college or have graduated, have a much better idea of what they want from life, and are going after it. Even if they have no idea what career they want, their desire to educate themselves and demonstrate their ability to learn and use their critical thinking skills generally puts them heads above the rest with regard to conviction, or purpose. Once they figure out what it is they want to do, they'll be all over it like a fat kid on cake.
I'm not saying people who don't go to college have no ambitions or drive, i'm saying people that DO go to college generally have more ambition and drive.
Except for Liberal Arts majors.
lol