No, what I mean is that people who went to college share a similar socialization process. I'm not talking about networking, I'm talking about culture. It's the same as people who went to high school versus people who were home schooled.
Everything from bonding (or not) with your roommate, to going out late at night with your hallmates, to meeting boys/girls and dealing with the strange dramas that ensue, your first off campus party, cramming in the libraries at 4am for exams, hanging out in the [insert major] lounge and complaining about your professors, tailgating at football games... just all the little incidental things that are part of college life. People who went through college can automatically bond over their separate experiences of these things.