We use out of as a preposition to talk about movement  usually with a verb that expresses movement (e.g.go, come). It shows where something is or was going: You go out of the office and turn left it can also be used to describe temporary insanity or stupidity in idioms: "he was really out of it" (he was drunk / sedated)"you are out of your mind" (thats a bad idea) "you need to think out of the box" (you need to think more independently)