Sometimes there isn't a dialogue. There's an inner monologue with two voices. A relationship dynamic you are building with yourself. A one-sided conversation that will never be reciprocated. Or would be volleyed in an entirely different way.
Sometimes the silence is so deafening that it feels safer to make up the other side. To fill in the silence with words you wish were said or fear will be said…but the truth is that until they are said this is all wasted mental energy.
Try not to react to what isn't there.
That's my advice to me. And you, if you want it.