Back when I was trying to make the uberman (and eventually the everyman) sleep schedules work for me, I ran across a person like you, it made me incredibly jeal

Back when I was trying to make the uberman (and eventually the everyman) sleep schedules work for me, I ran across a person like you, it made me incredibly jealous. He seemed to think it was that his brain only went into REM mode for some reason. As the other comment mentioned maybe it's just a simple gene mutation, if so perhaps CRISPR can replicate the effect... Lots of stuff if you google "Short sleepers".