Best Friends...Forever?

Do best friends forever really exist, or is it an urban legend someone made up a long time ago?

I'm dealing with the fact that a close friendship I had has changed and that change means the end of us being friends. Someone that I met when I became "an adult", someone who I thought would be someone I could "grow old with" in the friendship sense. I thought that since I was a "grown up" now that friendships would be more permanent. 

My issues with "forever" friends started in third grade. That was the beginning of the end for me. My BFF was Whitney. She and I had been friends since first grade and we were super close. I always imagined growing up together and living out the big moments with her. Then one day I went out to recess and Whitney wouldn't talk to me. I don't know why, we didn't fight, we had been laughing and joking earlier. She kept sticking her tongue out at me and making mean faces.

I devastated. My third grade self just couldn't understand. What did I do? I thought we were friends? Still kinda breaks my heart to this day. 

My ex-stepfather, David, was another one. Our story is a bit too complicated and long to include here, but I think he was the best friend I'll mourn the most. Kinda like how Fry's dog sat and waited for him to come back for the rest of his life after he was frozen (if you watch Futurama, you know what I'm talking about, otherwise you can see the part of the episode I'm referencing here...makes me cry every time). 

Source

I went through enough "best" friends that for several years I refused to refer to anyone as my best friend on the off chance that maybe I was cursed and that saying that is what caused the end of the friendship. It wasn't until Dave came along that I was comfortable in knowing that calling him my best friend wasn't going to make him go away (nor was anything else that I did to possibly annoy him). 

So the point of all this is to ponder, does forever really exist when it comes to friendships? I don't mean spouses or siblings, but friends. People who have a choice of whether or not they are going to put up with you. 

I mean obviously its possible, my sister and her best friend have been BFFs since elementary school, but when I look back at their relationship, I feel like they were fated to be forever friends. When we moved, they made it a point to keep in touch, when they went to high school, they found out they were going to the same school...I mean come on, what are the chances of that!?! My family moved A LOT when my sister was young, what are the chances of her best friend moving too and them ending up in the same place? Fate, people, fate. 

Crystal always let me tag along, she was like another big sister.

But I feel like their friendship is an anomaly. It's rare. I feel like there is more of a chance of best friends moving on from each other than growing old together. People change, I know I've changed and the friend I'm losing has changed. When that change happens, maybe the compatibility that once was there, no longer exists, which means forever is damn near impossible. In order to remain forever friends, that would mean that we could never change as people. 

What do you think?