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!
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!