In Betty Edwards’ excellent book “Drawing on the Right Side of the Brain”, she has students draw something, and then draw something upside down. The upside down version is invariably better. The reason is, people don’t understand what they are looking at, and so the only thing they can do is copy the abstract elements, the lines, where they start relative to each other, at what angle they slant, et cetera. And then the drawing just magically re-appears again on the page.
Our eyes are constantly filtering out information. We are bombarded with data, and the brain reduces everything to symbols. If you see a lion walking the streets, your brain reduces it to something on four legs (can run fast!) with teeth (that can eat you!) and you run.
You don't remember how the line reflected in its fur.
And yet, that is exactly the thing you need to notice when drawing a lion. You have to learn to see, to notice, all the abstract elements of everything, so that you can start to depict it realistically.
You don't have to draw everything upside down, but it does help to draw just the abstract elements of the thing you see, and not the symbol as you think you remember it.