A very popular tagline for the movie "The Dark Knight". The phrase has achieved a level of popularity, earning it spots as an internet meme, several XBOX Live account names, and something for 13 year olds to put in their signatures on forums to be scary and angsty.
By the year 2018, this will be the new "Where's the Beef?!"
20 Years After the Dark Knight...
Person 1: Remember that dumbass who got "why so serious?" tattooed on his shoulder?