Physical strengths are blind raw desires whereas our neshama sees and understands. When the body does not listen to the neshama (soul), the body follows its own wild desires. We can make believe that we are frum but what we really want cannot be faked. The neshama (which is crippled) needs the body in order to carry out the purpose of being in this world whereas the body (which is blind) needs the neshama for direction. The "Aish Kodesh" explains to parents that children have their own direction. Imagination takes the feeling of hunger and changes it into a desire for pleasure so that the pleasure of eating becomes the purpose of eating.