It’s a bit like wiggling your ears, or your little toe sideways. Everyone can do it, some people don’t know how to make the muscles fire correctly. Once you can do it, it’s so instinctual, you can explain HOW to do it.
I can easily see some people not learning that particular motion with their hands, it’s not a particularly useful one, and so won’t be noticed as missing.
It’s a bit like wiggling your ears, or your little toe sideways. Everyone can do it, some people don’t know how to make the muscles fire correctly. Once you can do it, it’s so instinctual, you can explain HOW to do it.
I can easily see some people not learning that particular motion with their hands, it’s not a particularly useful one, and so won’t be noticed as missing.