My PhD student came by my office to talk about his work. We didn't have an appointment, but I'm generally fine with it, when they have something important to discuss. So he came in and started talking right away, even though he was still chewing on his sandwich. And he didn't stop eating after he had finished the first bit, but worked himself through his sandwich and his thoughts simultaneously munching and talking. It was so unusual to me, that I watched him amused for quite a while, but finally I told him, that I think it's a bit rude to talk to me while he's eating. But it seemed that his whole brain was occupied already with the munching and talking activity so much, that my complaint did not reach any significant parts of it. He just nodded, made some "ah OK, I understand!" sound and continued eating and talking until he had finished his food and what he had on his mind!