Shit talkers

There comes a time when people begin to talk about you. I'm more simple words they 'talk shit'. But why do people do that? Why talk about people especially when they know you're talking about them. Is talking shit a way that we use to to spice up our own life or to escape from it? Honestly talking shit won't only the person you're talking about (if they find out) but it will also hurt you. The instant someone knows that you're a shit talker, people would automatically know that- that person isn't a reliable one. So I ask myself this a lot, why do we still like to know about the shit they shit talk about, when it's a bad thing?