You both love to reminisce about the past. You have hundreds of terrible pictures of each other. You know your best friend's family well. You're always honest with each other. You “Like” everything they post on social media. You talk to each other all the time. You always have each other's back.
Your high school best friend was the one who stuck with you through your awkward stage, guided you through the “WTF, I'm supposed to put his what in my.