Portal addiction
When a person loves Valve's two games Portal and Portal 2 so much that they can't stop playing it, thinking about it, or searching for more Portal-related content. One suffering from portal addiction can either be addicted to the gameplay itself, or even the storyline and characters. Sometimes, said persons will turn to fan fiction, unofficial mods, or portal-related websites for continuation of the Portal series storyline.
All Jimmy does is play Portal 2 and read fanfic about Aperture Science; I think he's suffering from Portal addiction.