I told him he was acting like a 'bonehead'. [='numbskull']
a 'bonehead' [='boneheaded'] decision
a 'boneheaded' mistake
(..) I could have sworn the guy said south. But then, all of a sudden we're off the main road. I'm trying to read the map while I'm driving, which is a bonehead maneuver. And all of a sudden... Bam, we're in that ditch. Yeah, bam, I'm like, what the hell? You know? Yes, and my coffee mug. (..)2008 TvShow: Breaking Bad Title: Cat's in the Bag... Season: 1 Episode 2