Used to describe a public preoccupation with matters of an emotional, sexual, or other such nature. Most noticeable when a member of a social group is distracted or despondent whilst thinking about their object of desire, despite hi-jinks or drunken revels by the majority. Also pertinent to those who have been dumped, are dumping someone, have been rejected etc.
"Where did Steve go? I thought he was getting a taxi with us?"
"Nah, he went off on an emo quest about half an hour ago"
"Is Jason coming tonight?"
"I hope not, all he talks about at the moment is Rebecca. He's on a total emo quest"