One doesn't know an answer to questions like "how are you doing?"
Someone is doing you a favor and you don't care, hoping it won't show on your face.
Someone is thanking you for a service and you reply with something like " thank you for offering the opportunity"
Walking in a beautiful park you don't feel beauty, only a void and you forget both the beauty and the void.
Dreaming to be walking in an unknown city, you suddenly find out to be naked but no one notices it.
Someone says something you could never agree with and all you do is ask: "do you have something to substantiate
that?"