A mingehead is a person who says or does silly, stupid or retarded things. If a person looks like a mingehead they are usually very ugly and quite scroaty/chavy. This person usually smells (has BO)and has greasy hair because they dont wash very often.
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.