Before the invention of the camera became prevalent, portraits of people were all done with pencil/charcoal/chalk and/or pastels. Those charcoal and pencil portraits looked exactly like a bloody photograph and the only way to tell it was done by hand is to examine the picture up close- then one can see the strokes.
As we know, back in those days people posing for portraits had to sit for a long time, lol... um.. even when the camera first was used people still had to sit for a very long time trying to maintain a pose. However, there was an artist who used to draw portraits for people, he had something of an eidetic memory. During the morning hours he would have 4,5, or 6 families/people come in and sit down for portrait poses, then do a rough sketch of them and send them home. Later, he would produce finished hand drawn portraits, that looked like a photograph...
Your work is very reminiscent of someone with an eidetic memory because the artist I mentioned above claimed he could literally project the image from his head onto the canvas and draw over that image, allowing him to produce vivid and extremely precise photorealistic art. Is that kind of how you work? Some of your drawings look as if straight from a photo, lol, and they are vividly perfect.