It's not that I'm incapable of having internal dialogue, it's just that it is putting in words others could understand a thought, or series of thoughts that happened in fraction of a time it takes to form a single sentence. The result of the thought process isn't something expressed in words, it's internalized knowledge, conclusion or decision
I don't feel singled out, I feel inclined to think that most people do have internal dialogue, but for some it's after the fact, it's not part of the thought process