"he's got plenty of brains but no common sense"
"his mind wandered"
"I couldn't get his words out of my head"
"Mozart was a child genius"
"he's smart but he's no Einstein"
I've had this tune on the brain all day but I can't remember what it's called.
我脑海里整天回荡着这个曲调,但我想不起来叫什么。