Ok. I will give you a practical example. I am assuming you are a decent driver, with a wheel. Otherwise this won't work.
Get a stock car, that isn't afraid to kick it's tail out. 458, SLS, doesn't really matter. And have it on sport hards. Just no racing cars or anything, otherwise doesn't matter.
Go into practice mode, set SRF off ASM off etc. TC can be at 0 or 1 or something. Low.
Go around a corner and wait for the tail to kick out, to the point where you need to correct it to stay on track. And watch what your hands do. If you are anything like me, or any decent driver I have ever seen, you just correct it. That quick countersteer jerk and the moving the wheel to center.
You don't have to think about. It just happens. Because it's been done so many times, as soon as your eyes see it or your hands feel the FFB, your brain knows exactly what to do and does it.
Now, the feedback would be different in a real car, and it would take a few corners or laps to learn them, but after that, the muscle memory stays the same. The motions you make with your hands are the same.
That's just one example. Can you get that same muscle memory from hours and hours in a real car? Yes! Would it be better? Maybe. Probably, in fact. But it can still be learned in GT5.