Keep the people who knew you before you were interesting.

Before you had anything anybody wanted, some people were around anyway. That matters later, because once you have something going on, it gets hard to tell who likes you and who likes the access. The old ones have no such ambiguity; the evidence was collected when there was nothing in it. They also remember you as a person rather than as a thing you achieved, which is a useful mirror to keep.

Keep two or three of them. Call the friend from before, the one who has no connection to your current life. And notice if you only make time for people who are useful to you now.