They can't be there. I haven't been into the living room since I come back home.
Well, I don't know then! Did you leave them in the car?
I can't have left them in the car. I locked the car when I got out.
Hey.wait a minute. There they are! They'te still in the front door!
Oh, I must have left them there when I came in.
Honestly! You'd forget your own head if wasn't screwed on!