I am not sure who my best friend is. I could tell you who they were throughout time... Marie from elementary school through freshman year of high school... Robbie in high school... Lizzie and Catherine in college... maybe even Lorene in graduate school. But after that, how do you define a "best friend"? Doesn't the term seem weird once you get past 25? And I am not going to define my husband as my best friend, Bachelor-style.
I will describe my oldest friend in great detail. My oldest friend is Blanche. We met in girl scouts - her mother was a troop leader, so even though she was a grade above me in school, we interacted on a regular basis. In middle school, the librarian introduced me to Anne McCaffrey's young adult books, and I fell in love. On the bus home, I described how great they were to my friend Marie. Blanche popped her head over the seat in front of us, looking back. She broke in, "You know, there is a whole series based on that!" Marie and I uncomfortably smiled at her. But after that, Blanche and I would exchange books and book recommendations.
At home, I could find the whole Mission: Earth series by L. Ron Hubbard. My stepfather told me I wasn't allowed to read them, but I sneaked them to school where I would lend them to Blanche. We read them surreptitiously and trade theories about just what, exactly, was being satirized. I'm still not sure about why I wasn't allowed to read them or what was being satirized. I can't believe I read all ten of those books.
We continued our book-trading through high school, taking time in our friendship to create a live-action role playing game about vampires that no one ever played (including us). I don't think either of us would have said we were best friends, but we were friends. We went to each other's parties and whispered about crushes and kisses. Somehow, out of all the friends I had, once high school ended, Blanche and I kept in touch.
Although I got progressively less nerdy, Blanche doubled down. She gave me a ride to the Columbus airport once, the day after The Lord of the Rings: Return of the King opened in theaters. Of course we went to see it, so I was dead on my feet checking in. When we get together, we play board games or watch SF. We also have lots of heart-to-heart talks. We may not seem to have much in common anymore, but we can still toast our friendship with Benden wine and gossip about old acquaintances. We are comfortable together, and I think we will be friends for a long time still.