Fear of old things. From the Greek (palaios-, "old”) and (-phobos, “fear”).
Alice: I'm going to the museum. Want to come with me?
Bob: No thanks, old stuff creeps me out.
Alice: Why?
Bob: I dunno. Maybe I have paleophobia or something.
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.