I am just going to throw this out there. What is the nature of these friendships and why does this matter to you? Are these real life friends? Are these other peoples' responses gravitating towards people they actually know? I only make birthday wishes for example to people that are really close to me and it occurs to me that my 'likes' gravitate towards them too. Is it possible that you are speaking about people you don't know in real life? If in fact this is about people you don't actually know I suggest that your reaction might best reflect this.