Yeah, 13 years is such a long time not to reach out to the people you called your friends, but then, people are like this. A lot of so-called friends would neglect you when their lives becomes financially better or they travelled. I think it's a thing that people do that they don't consider to be wrong.
However just like I said, I have zero expectations from most people, so sometimes I already predict their disappointment before they even do it.