That the Body should be as relaxed as possible in all situations is not hard to understand. Anything else causes an unnecessary energy waste and in many cases it also causes damage to the body over time.
The neutral state for the Mind is a state with no thoughts except for the treatment of input from our senses. If all other processes running in the brain are shut down you get a clearer and stronger input from your senses.
The neutral state of the emotional centre is NOT no feelings, it is actually the feeling of Love. But it is love alone, not love in combination with excitement.
When the 3 centres are working like this the human brain are working as it should and we are ready to perceive the oneness and unity of everything around us. And as always it also works the other way around. If something in our environment causes us to perceive the oneness then the brain start to work as it should, the body become relaxed and we feel love.
Living like this will keep the body and mind in good condition for a long time.