Suddenly becoming obsessed about a single piece of work, a series, or a narrow area of pop culture. Similar to geeking out, though can be used to describe becoming obsessed with non-geeky things.
Nora is constantly spouting crazy theories about Inception. She's gone completely okapishit for it!
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.