Why do people get so irritated these days?

Honestly, why do people get so angry when others don't have the same mindset as them? Why do people act like they know you? I've never talked to and yet you're rude and on my case. Oh jeebus.
/rant over
:/

I don't know, it's really dumb because like there are super religious catholic people out there that would get pissed and talk crap about others if they believed in something else.
Also if they are ignorant and don't actually see things in other people's perspective gets kind of annoying, it's like their way is the only right way