I've been wondering about that myself. How can someone be so oblivious? There's no way! But I do believe that it's extraordinarily difficult for a self-centered person to empathize with other people. It's just not in their nature. They only see and feel themselves and all the real and imagined ways other people hurt THEM. So the short answer is: yes, it's possible to be that disconnected. But it doesn't mean they're not responsible for their actions.