Seriously, I think Sam is bipolar. Maybe more manic (a LOT more manic) than depressive - but the depressed side did show when he needed all those pep talks from Troy, when he fell asleep on the floor in the middle of crunch time on their project, & again when he refused to move from the door till someone "greeted" him. (LOL & WTF?!! Earth to Sam, your mom is not in residence here, and in spite of what she told you, the sun does not rise and set in your *ss.)
He's probably very bright, but w/o common sense, it doesn't matter.
OK, can we get rid of Ponderosa now?