the complications come about because there are as many internal environments on the planet as there are people. nothing is pure so there is nothing uncomplicated by environmental issues and genetic expression. the mind is the great healer - the body simply follows that, whether it is in error or not.
but no matter where you are at, you can look at this priciple and make deliberate choices to move in that direction. without this compass(a SIMPLE but useful instrument), how does a person know if they are going the right way or not?