Oh, and I do get more visuals on the edge of sleep. Vivid hypnagogic imagery, I'm pretty sure. But whenever I become aware of it and get interested, it quickly

Oh, and I do get more visuals on the edge of sleep. Vivid hypnagogic imagery, I'm pretty sure. But whenever I become aware of it and get interested, it quickly recedes from me. So I suspect that I have some hardware ability to visualize, but that it's suppressed by other things when I'm alert.