The "Know it all" .....

Yup. We allllllllll know one. and if we're really lucky we know MORE than one! And i'm sure we've all wanted to slap em or something or other. My question is "Why?". What drives someone to pop off and not even consider advice or  something? Granted one's personal experiences or beliefs may make them biased but come on! shut up and AT LEAST listen to what I have to say!! Get your head out of your *** and just listen..... You don't have to agree just shut up and listen...  and nowadays its not the older generation but young ones who are so stubbon and mule headed and feel they are right and you're wrong EVEN though you've already done it or experienced it.