A typical response to a dumb or pointless anecdote among friends.
Dude: So, today I was driving home from work and I noticed a streetlight was out.
Kid: ...Cool story.
when someone says something really weird. akward, or something no one cares, about, so you say cool story to be sarcastic and show that you didn't care.
"So I got buger king the other day cause my mom had a coupon for free whopper, buy one meal get one free. so I got my food and took it out to the truck. well I was driving and I wanted a drink of my coke. so I tore open one end of the straw paper and blew into that. And the paper shot off to the passenger side vent! Then I laughed and forgot about it" - Daniel
"Cool story" - Bri
When cool story bro became massively overused people find a way to make it less cliche.
A: Me and my wife have been married for 5 years.... blah blah crap.
B: Cool story bro.
C: ^^ You're really cheesy, just say cool story.