This behavior is often used as a compulsive and lame humor device in conversation which is an "epic phail" because it makes the humorist look like a credulous cretin instead of a sharp satirist. In actuality the idiot can't help but respond to everything they're reading or hearing and just has to make a comment, no matter how stupid. Often because the idiot doesn't know how to socialize normally.
Idiot: "Really? Why would you admit that you peed your pants online? You probably have some kind of bladder condition that you need help for."
Molly: "Really?? Seriously?? I didn't actually pee my pants, dude. Yeesh!"
Idiot: "Then why did you say you did?"
Molly: "WOW! Just WOW! This is sooo literal 'net!"