A friendship is a funny thing.

“Friendship” is a broad category with vaguely defined parameters, unlike many other relationships that a person is bound to have throughout his life.

If you have a boyfriend or a girlfriend, you know what that means. Generally, fidelity is expected, as is sex, affection, birthday gifts, etc. If you have a fuck buddy, you understand that fidelity is not expected and a go-with-the-flow attitude is. Servicer-customer, parent-child, employer-employee — all of these relationships are pretty easy to navigate. Most can understand the mechanics, the who-owes-who-what. People know that they should show their employer the utmost respect and not to expect as much back. People who don’t realize this don’t have jobs.

But almost everyone has friendships.

The dynamics of a friendship just aren’t as black-and-white as those of an employee-employer relationship. One reason for this is, obviously, that not all friendships are the same. Of course, people tend to have certain friends that they’re closer with than others, but it isn’t as if there is some standardized sliding scale: “I’m a five with him and a two with her.”

You have friends in your life that you only talk to in class or at work, friends that you see once a year and friends that you see every day. There’s also friends that you see every day but you don’t really like all that much. You aren’t always going to know what to expect out of a friendship. How much of a priority you are to someone else, how much respect or consideration is expected and other such questions often have some pretty loose answers.

Given all this, it’s no wonder some friendships can fizzle out or implode. And I get why it can be frustrating, but friendship is an important part of life.

It seems that the closest friends are the most care-free, who don’t worry too much about expectations or dynamics, because the fluidity of friendship is actually one of its best features. So what if you’re not always going to be friends with the same people. You’re going to have some friendships that end. But you’ll have had the experience of being friends with so many different, interesting people nonetheless. And unlike many other more rigidly-defined relationships in life, friendships don’t have to end. You don’t break up with your friends. Friendships have the potential to evolve radically, and it’s that evolution, the ever-changing nature, that makes friendship so rewarding.

So enjoy it before you get old and die.