His shoulders hunch, without him quite meaning to do it. "No sir -- uh, ma'am -- I was just thinking is all. About things. Um."

Yeah, he can't even come up with what he was thinking about before Major Houlihan arrived. He doesn't want to sound like he's complaining, either, which he's sure'll just get him a smack on the shoulder and a stern order to buck up. But he says it before he can stop himself: "It's been a real long week and I didn't sleep too good last night."