Public opinion is something people consider to be one of the important signs of mass recognition. If people like you and smile to you it automatically makes us think we're perfect, friends, co-workers or girlfriends/boyfriends. When something goes wrong in someone's attitude towards us we fall into euphoria and start to think it's our fault. Why? May be because we don't know the true reason of what's happening.
People always care what others think of them. May be it's because we tend to look perfect in everyone's eyes but as an old adage says "You're perfect when you don't do anything". Any of your activity will rise negative or positive reaction of people because no one thinks the same. SO may be we should stop worrying about what others think because it's impossible to be good for everybody.