When separating the bones and the meat, finding the intrinsic stillness of bone is a big leap. What's next? It's simple, bones are hard, meat is soft. Why then can the bones feel soft? For the beginner, this makes no sense. As the resolution of your bone perception increases, what at first feels soft is just the 'elasticity' of the bones and meat working together with coupled power.
We must remember that, while detailed anatomical abstractions are useful, they don't help us train. We have the 5 Mental Models and 5 Movement Primitives to help guide our practice. Softness changes depending of which emphasis is currently under consideration. Sometime in the future, you will find that softness feels hard and hardness feels soft. Yeah, I know, doesn't make any sense, clarity as to 'why' will come, just keep training for now.