Best friends are great, but you need casual friends too. Casual friends are the type for friends you see from time-to-time, rather than constantly. They're still good friends and you trust them, but they might be new friends or friends you see irregularly for drinks, rather than the kind of friends you binge watch TV with on a Friday night or plan future vacations with. Casual friends are often there in group situations, and when your schedules and find time for one another (you might not actually cancel plans to see a casual friend, and you both understand that as being the nature of your friendship). But casual friends are still super important in the scheme of friendships.
Different people bring different things to your life, and just because you don't call someone your best friend it doesn't mean they're no valuable to you. There's value in casual friends, party pals, soulmates, romantic partners, and besties. Everyone you spend time with it enriches your life somehow (even if that's hurting you in a way that teaches you something about yourself). Other people are how we find happiness in the world, and having different friendships can also bring out different parts of our own personalities to teach us more about who we are, and how to be happy with that.
1. It's Relaxing
Casual friends take the pressure you feel with your best friends off. For instance, a best friend might expect you to turn up to certain social occasions, and you will, no matter what, because you love them and want them to show the that. But sometimes that's exhausting. A casual friend is someone whose slam poetry recital you can politely decline, knowing that there won't be any hard feelings at all. That's a pretty relaxing friendship.
2. You Can Explore A Different Part Of You
Close friends have inbuilt expectations of who you are, and most of that is because they know you so well. A lot of it is also because they know you so well and baulk at changes in your personality. Meanwhile, with casual friends, you can bring out the funniest side of you, the darkest side of you, or any other side that naturally comes out when you're around them, and they wont wonder where the "real" you went. Although it's not that you're not being "real", you're just highlighting a different part of your personality.
3. You Gain A Different Perspective
Sometimes you can predict the advice your close friends will give you. And with close friends, more often than not, you might all have similar opinions on things anyway. A casual friend can be someone who you don't have enough in common with to see regularly, but enough that seeing them on occasion is fulfilling, especially because this person might offer radically different insight than you're used to.
4. They Bring Variety
You can fall into familiar patterns with good friends. The same memories that you talk about, the same bars that you visit, the comfortable routines that you love doing together. And that's wonderful! But sometimes a casual friend can bring variety to your life. Maybe they'll invite you to a social event where you don't know anyone, or an activity you wouldn't normally do with your close friends.
5. You Can Be Honest With Each Other
There's a strange clarity that comes with talking to someone you trust but aren't that close to. Because you don't have any personal hangups with a casual friend (for instance you might have resentments built up over 30 year friendships that don't exist, or a sibling dynamic that makes you a bit of a wuss when it comes to criticism), you can express yourself honestly, and accept and give honest advice in a way you might not sugar coat the way you do with close friends. While you're still honest with your besties, it's just different with a casual pal.
6. It's A Very Grown Up Sort Of Friendship
Being that you don't have the emotional attachment that makes you joined at the hip or offended when the other isn't available, casual friendship feels very grown up. You also probably do more activities, or nice things like dinners with wine, rather than bar hopping, simply because your catch up time is catch up time and revolves around actually talking about material things happening in your life.
7. A Lack Of History Can Be Refreshing
Not having to have the time you did X embarrassing thing in high school come up all the time can be really refreshing. You might not have the kind of dynamic history you have with your best friends, but the great thing about a casual friend is that the two of you have your own special history.
8. They Fit Into Your Life Conveniently
As much as you love your friends, having to bend your other life commitments to fit them in can actually be stressful. You do it without complaint, but it would be nice to sometimes skip the friend hang and have a nice night in alone without feeling guilty about it. Your casual friends fit in when they can fit in, and that means you only see each other when you want to see each other and aren't overly stressed about a million other things.