It's so unbelievably irritating that I'm actually fluent while talking to myself, reading, or singing.

It's so unbelievably irritating that I'm actually fluent while talking to myself, reading, or singing. How does any of that even add up. When I need my fluency the most, it completely fails me. Could it be that stutterers are focusing on the wrong verbal cues when communicating with someone? That when they're directing their words at a person, their brain shifts from merely reciting those words through familiar muscle memory, to being overwhelmed by extra stimuli from the social interaction that's involved and therefore going through different pathways that happen to impede each other?