"MBA Classmates versus Real Friends" or "Colleagues versus Real Friends".

From the link: http://www.wetfeet.com/advice-tools/on-the-job/work-friends-vs-real-friends

(Please read the full article from the link above. This was not written by me)

An important lesson about work friends vs. real friends: It’s easy to mistake one for the other, especially when you’re struggling to establish a social life. In school, making friends is as simple as walking over to the dorm room next door and plopping down on the bed. After college, there are no such opportunities. Because you might be too busy to go out and meet new people, the tendency is to target your coworkers. It makes sense. After all, they might be the only people you know that are your age, and you see them for eight hours every day.

While many people use work as a springboard for building strong friendships outside the office, I wouldn’t assume your colleagues are your new best friends just because you take your coffee breaks together. There are differences between close friends who will be there for you through life’s tough times and people you hang out with while you happen to be stuck in the same building. You can spare yourself disappointment later on by noting the differences between a work friend and a real friend. Here are some questions to ask yourself:

• If your friend left the company, would you still be in touch with her in a year?
• If you had a personal emergency, would you consider asking your friend for help?
• Do you hang out with your friend outside the office? (Weekday lunch, happy hour, and business trips don’t count.)
• Have you met your friend’s significant other? What about her friends outside the office?
• If your friend received the promotion you were banking on, would you be genuinely happy for her?
• If you ran into your friend in the grocery store, would you be able to talk to her for 10 minutes without mentioning work?
• Have you seen where your friend lives?
• Do you and your friend have anything in common besides your age and your job?

If you answered yes to most of these questions, you might have found yourself a real friend at work. Take care of this relationship by making a concerted effort to spend time with your friend outside the office. You and your friend should also avoid working together too closely. Like living with close friends, being in business with them can sometimes be disastrous. Whether we like it or not, people can behave differently when money, power, and careers are at stake. Suppose you and your friend pair up for a high-profile, new business project. Your friend could be the kindest, most generous person in the world after quitting time, but she might take all the credit and do none of the work in the office. You don’t want to put yourself in a situation where you must choose between your friendship and your career.

If you’re lucky, your classmates / people you meet at work could turn into a friends for life (and not just Facebook friends, LOL :) !