Thoughts and sensations may be far from totally obedient to the will, but the physical world is much less controllable to someone who is young. They might try to flee from it, into an imaginary world. At the same time, thoughts of pain and confusion actually distract them from their bodies, and the physical symptoms of their stress are just allowed to happen. Physical symptoms can seem unpredictable, so a child doesn't try to understand them so as to alleviate them; or they can seem inevitable, uncontrollable, and thus not worth tackling.
