Life in the real world is very sobering to the recent college graduate. People do not randomly sit next to you while you're eating simply to potentially make another platonic friend. You spend considerably more time on making money and keeping track of your personal finances to make sure you can afford to live without discomfort. You lose touch with your friends from college unless you make somewhat of a dedicated effort. People only socialize with you if you can be useful to them in some way. If you are single, feeling lonely can also come quite easily. (However, being single is much better than being in a destructive relationship.)
All of this paints a very bleak picture of life that seems distant from the rosier ones from our younger years when we simply spent time with others because we enjoyed their company. Who are the people who actually care about us and love us for who we are?
For the overwhelming majority of us, those people are our parents, siblings, grandparents, and other family members. Only after graduating from college did I truly form a far deeper appreciation for my family and how important family is. When all else fails, your family can back you up and support you through hard times when no one else will. That's not to say that you shouldn't be self-reliant but you know you have a strong safety net. (I understand that some people do not have this, through no fault of their own. In these cases, I see the value in belief in an all-loving god and establishing charitable organizations, religious or secular.)
My theory is that the people who love you the most are your parents and the people you love the most are (or will be) your children. You should not lose sight of this but you should not be too distracted so that you ignore people who are not related to you. Looking back, forming deep friendships was easier as a student and I did not do a fantastic job of maintaining those relationships with the best of my abilities. I would advise college students to really appreciate the people in their lives and try to maintain those relationships after graduation as well.
Placing a high priority for your family life changes your attitude in dating as well. If you want to get married and have children and that is ultimately what is important in the grand scheme of things, then you should probably approach relationships with some degree of seriousness. I'm assuming you'd want an intelligent, kind, patient, and understanding partner. If that's the case, should you really be at a bar or nightclub getting wasted to lower your standards for a quick lay? Again, you'd have to decide that for yourself since you are the only one who can determine what you do.