A sarcastic phrase often used to question and belittle a person who has told a long story full of boring mumbo jumbo bullshit, that doesn't have any single significant point.
Also see cool story bro.
Person A: "So I went to the mall today and" etc...
Ten minutes later
Person A: "... so I bought one for my Cat."
Person B: "Did you find $20?"
Person A: "No."
Person B Leaves