Situation where someone treats someone one way, usually negatively, and then at a later point in time regrets what was done to that other person in the past or begins to treat the same person in a more respectful manner. Identified in the 1988 Biz Markie song "Vapors."
Girls dissed you because you were broke. Now that you blew-up and have money, the same girls want to get with you. These women have caught the vapors.
Guy breaks up with his girlfriend. Later on realizes that she was all he ever wanted and that breaking up with her was a mistake. Now he wants her back. He's got the vapors.