Part of that, of course, is the fact that college for many involves moving out of your parents’ house (and away from adult supervision), being in your late teens and early 20s — basically the perfect formula if you were looking to concoct intense experiences.

If the people you shared those experiences with stayed in your life and on good terms, chances are you forged a pretty strong bond.

But it’s also about the intimacy that occurs when you live so close together, the friendships struck up when you’re both waiting for the dryer, when you wander into a conversation in one of the common rooms, when you join forces with another sworn enemy of the loud music player down the hall.

And while hostels — hotels more common in Europe than the United States that have anywhere from four to 20 strangers sleeping in a room together, and shared bathrooms and kitchens — don’t have the same residents for a year, their similar design encourages that intimacy.

To use the behavioral buzzword of our time, dorm life is one big “nudge” toward friendship.