The other side

Have you ever found yourself waving your hand at a stranger on the other side of a windshield and the stranger actually makes funny faces at you. He is doing it to his reflection on the windshield. He can't even see you. But then you are perturbed, feeling "Why did he do that?". Then, if you were smart enough, you would realise the parody of the circumstances and walk away, shaking your head with a smirk on your face.

But what if you weren't smart enough like me. What if you thought there was something wrong with you?