With social media, the cliques that have always dominated high school cafeteria follow everyone home. With this, the kids who aren't "cool" or "popular" while at school, are now not "cool" or "popular" everywhere they go. For some people, not being the cool kid feels sort of depressing, or perhaps they are missing out on something. I know for my entire life, I have never felt like a "cool kid." But I'm here to tell you that it's okay to not be the most popular kid in school, or even well-known at all, for that matter.
Just pause for a second with me. Imagine your life in five years. You will be in a whole other stage of your life. Your popularity now, or perhaps the lack thereof, could very well not affect you in this next stage of your life. So why does it matter whether or not everyone at this current place knows your name or waves at you every time you're seen? It doesn't.
Sometimes it feels like you get left out because you don't have as many friends as those cool kids. But it's okay to not have a bunch of friends. This gives you the opportunity to have closer friendships and relationships with people. Having a few friends instead of many allows you to be involved, your friends are more like family instead of just people you hang out with from time-to-time.
It can feel a little lonely, though, when all of your friends are busy at the same time. This could lead to you trying too hard to fit in more at school. But please remember that fitting in should never, ever mean losing yourself or your identity. You should just be yourself, even if that means people don't like you. When you find someone who does like you for being you, they will just be that much more special to you.
Being "cool" or "popular" doesn't mean you will necessarily succeed later in life, either. The most popular kid in school could become the person with the worst job in town, or someone who can't let go of the glory days of high school. At the same time, the person that no one really knew could very easily become the next greatest author or president.
So, not being among the popular kids now doesn't matter. You don't have to be a "cool kid." Just be you.