No one really teaches you how to make your friends feel good. At least--no one taught me. No one said, some of your friends will need words of encouragement. Some of your friends need physical time spent with them to affirm your friendship. Some just want you to ask about their day, or check in on them, or buy them a birthday present.
And so, we lose the friends that we don't take care of, and we lose friends who don't take care of us. But that's okay, because it's part of the learning process. Next time, you think, I need to do better. (Well, that's what you should probably be thinking.) It isn't, I need to get better friends. Okay, that may be true. But, it should be: I need to be more receptive to their needs, and vice versa.
Growing up, I had a best friend, as many kids do. But then life--elementary school, middle school, birthday party drama--got in the way, and we fell away from each other. Then, I had a group of best friends in high school. I didn't nurture their friendships, and I lost them. It wasn't a one way street there, either. It wasn't just me, just like it wasn't just them. We all got it wrong. I discovered, though, that I didn't want that to be how I held onto friends. That is to say: I didn't want to be white-knuckled, holding onto them for dear life, afraid that they were going to leave. They did leave.
It led me to think: I need to be better.
Now? I have a great, solid group of friends. They're all over the country. I have a rough idea of what they need from me in order for me to be a "good" friend. I have a rough idea of how I can help them feel good about themselves--sometimes. Sometimes, I'm wrong. Hey, that's life. I'm still learning.