From Digital Minimalism:
The idea that it’s valuable to maintain vast numbers of weak-tie social connections is largely an invention of the past decade or so — the detritus of over exuberant network scientists spilling inappropriately into the social sphere.
Those 50 people you short of knew in high school, but never really talked to don’t matter. Why are you spending any time worrying about what they think of you on Facebook? If you don’t care enough about someone to schedule a regular time to see them face to face, or to have a phone conversation, the relationship likely isn’t that important.