Board Thread:Naruto Discussions/@comment-30180929-20171203120926/@comment-1512913-20171203124116

That's exactly why. Stronger/greater spiritual energy = superior intelligence and empathy.

The more intelligent and emphatic you are, the more you can understand the world and people around you and feel it. The more you understand things and the more emotional you are, the more burden it has on your mind. For example, when a bad thing happens, a retarded person won't be burdened by it, being mostly oblivious to gravity of things, but it will weight on mind of someone who understands the gravity and it will be an emotional experience.