Physical changes
The body is honest. If you practice, it responds and develops. If you do nothing, it deteriorates.
This is just as true for wood carving.
In the beginning, many people try to carve using only a few fingers of their dominant hand. But as they improve, both hands—left and right—begin to work together. Eventually, depending on how they carve, the arms, upper body, and even the lower body start to engage. No amount of thinking can substitute for this feeling—it can only be gained through repeated physical practice.
The same goes for developing a sense of three-dimensionality. As you train your eyes, your ability to see forms in three dimensions changes. You start to notice distortions, misalignments, and the overall balance of shapes. This too can only come through repetition. If you look at three-dimensional objects without focus or care, you’ll never be able to truly grasp them.
This kind of development has little to do with age. If you’re struggling now, it’s usually because your body simply hasn’t been trained to move or perceive in that way yet.