The most suitable response one can give to a story that completely wasted ones precious time. Parents, co-workers, and history classes often provoke its usage.
Bobby: So guess what? Nina wrote me up again, because i came to work late the other day.
Kelly: Cool story bro.
*FML why does Bobby think i give two shits about his life??? Please lord have this shift end already! He makes my job REAL RUDE*
Teacher: Agriculture was key to economic progress in the early ages.
Student (shouting): COOL STORY BRO!
Mom: When i was your age i always had my room spotless.
Son: Cool story bro.