When Dyon was reading on body cultivation and energy cultivation, he was hard-pressed to understand the difference between them. This was because energy cultivation begins with body refinement, and the body must get stronger in order to accommodate higher level energies as your cultivation improves.
But, if you need to improve your body to cultivate energy, then where is the line of difference between body and energy cultivation? It just seemed as though everything was connected to the point where understanding was impossible.
And if that didn't make matters bad enough, you also had to include soul cultivation in the mix, while also taking into account that you need a stronger body to accommodate a stronger soul.