An internet style response for a period of interactive amusement followed by an abrupt realization that you are no longer
amused. Legend has it that Queen Victoria uttered the phrase right
before her much more famous phrase, "We are not amused."
mean that you were
laughing along with a joke
and didn't get it, or when you finally did get it, you didn't like it because you realized that you were
of the joke
, or it could
be when you have just realized that the speaker was not joking.