CBA is a severe form of laziness.
Often comparable to a psychological/medical condition. CBA is most common in teenagers around the age of 16-17 years of age.
Person 2: Nah, I've got a severe case of CBA.
Person 1: What's wrong?
Person 2: I'm suffering from a chronic case of CBA.
Steven: "Hey look, Nyan Cat!"
Joe: "Looks like my deep philosophical musings have been Thought Blocked once again."
Me: You must be fun at parties.