Ask HN: How many people switch besties every 2 years?

I'm one of those people who switch besties every 2 years.

My latest just broke up with me when they realized I don't consider them a bestie (but they did consider me a bestie).

My longest bestie-ship: 2 years. The shortest: 1 semester.

Please define BESTIE however makes sense to you. I consider a BESTIE to be whoever I think about the most when I don't think about myself (FYI I have no biological children).

I'm being deliberately vague so I can get a wide variety of responses.