Well, I didn't find it either, but maybe I just took the board for the main page. Because on my board there are only things that got posted there by other people like birthday wishes (ugh, don't post them, stupid humans ;>_>), but the main page shows what everybody likes and comments on. Maybe I just got confused with those two. I was sure it's somewhere in privacy settings, I remember a long time ago I was doing something there.
Anyway, I don't like things that much anymore anyways, I hardly ever log in to FB

I only logged in now to search for the options XD