That was long ago, when I studied art anatomy. Well, it was different from medical anatomy, because we studied only forms and construction of the visible body.It often happens that we look at something but don’t see it well. Sight is an important thing, but even more important is the mass and structure of something.
I note drawing skills of sculptors are just as important as those of painters, but they emphasize structure more, sight is not so important.
Human body can be transformed into basic shapes - spheres, cylinders, columns, cones - but this simplifies drawing. These studies are not art yet, but need some life (small details, lights, dynamism) to become real art.
You can be wrong. If you notice and fix it, that's okay. If, on the other hand, you don't fix it, you make a mistake.