1. The increased release of endorphines and thus heightened amusement upon witnessing successful "trolling".
2. The mixture of hilarity and incredulousness
experienced upon a person's obvious incomprehension of sarcasm when they respond to a sarcastic remark in all sincerity.
Modern usage:
Mostly adapts to a social situation, usually a
conversation, in which multiple people inept at
understanding sarcastic remarks or the true meaning behind feigned incomprehension (in continuous form: "trolling") take part without realizing they're being fooled for a longer period of time, no matter how ridiculous the foolers' comments may become.