It's fine not to know everything. This applies to intellectuals pursuits and to social ones as well. You can quit all social media (or at least ignore it for the most part) and nothing bad will happen to you.

You'll probably be happier for it.

My boss pulled up Facebook today and my response was, "Is that what Facebook looks like? I haven't looked at it in years." He said that was a cool thing to say. I'm not saying this to make myself look cool, I'm saying this because it's obvious that people want to get away from social media but they feel like they can't. 

So let yourself miss out. It's fine. You won't die. You'll have more of your time back. You'll be happier.