I miss my old friends so much.
The sad thing is, old friends only really ever separate by drifting apart, which means there's never really any closure. I think this makes it hard because you don't really see it happen. Just one day, you find yourself not rushing to tell them the exciting thing that just happened, or finding yourself ask someone else for advice instead of your trusty bestie. Then, before you know it, you walk round school with only the trace of a smile at each other as you catch their eye.
You can easily agree you have new friends and good friends and passing friends and kind acquaintances but no one will ever replace your oldest friend, will they? You can love them equally but they're two different people, and as selfish as it sounds, you need them both.
personally to you
"special friend" I miss you so much. I miss eating pringles in the coop car mark and i miss waiting around bored for my mum to stop talking. I miss playing with our dolls and fighting over game rules and story lines. I miss having sleep overs with you where we got nice treats and planned to stay up all night but lasted only a couple of hours. I miss confiding in you when things got tricky or when I fell out with someone else. I miss going to restaurants with you and your family. I miss your parents. I miss being so ignorantly happy with you. I never even considered you not being there with me. You were my second older sister and my best friend in the whole world. You really were a part of the family and I'll always, always remember how we were even if we aren't the same people any more.