A lunatic with retardation. The word usually applies to drivers. The word that comes to you while watching a driver in Washington or California stop the entire flow of traffic to let someone out of a parking lot. Or a driver that gets into the right lane from behind you only to cut you off because they had to turn left.
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.