Why do we let society constructed boundaries shape our lives?

What I really mean to say is, why do we not live our lives exactly the way we want and instead immediately conform to fit the standards that modern civilization imposes on us? I know I probably sound like a deluded punk kid with a pair of earphones jammed into my ears with The Casualties blaring at full volume or a whining hippie with a bong shoved far up my ***, but I was just thinking about why people pursue and mold their lives into one that benefits society instead of being true to themselves so long as they infringe on anyone's basic human rights or harm themselves and anyone else? Just curious to see what everyone has to say.