The act or pleasure from masturbating to pornography or pornographic images you have not seen for a long period of time.

(Usually directed toward internet porn where the long and somewhat never ending links to pornography make it statistically improbable to unintentionally find the same video, image, or file twice.)

when you're hungover as shit after a spending a night drunk as a skunk

When the nostalgia factor is so great, you nut

When a group of girls reminisce on past penis experiences.