When your first friend got you that "BFF" necklace when you were little, you never realized what it actually meant. You each had two halves of a heart pendant around your neck and it probably only cost $15 at Claire's, but even now, that little bedazzled pendant means the world to you. You two didn't realize it then, but since, you've put the 'forever' back in 'Best Friends Forever'.
Some besties are just like that. They are your day ones, your ride-or-dies, and the ones you're calling to pick you up at the drunk tank after a wild Saturday night. They've known your every secret since the 2nd grade and they'll probably know which grandpas you have a crush on when you are in the old folks home together. Some say that marriage is forever, but for you, your best friend is the one you're planning to grow old with.