Because all living entities are by constitution eternal servant. That is their healthy position. So long they remain servant of the Supreme, that is healthy. Same example, I have given many times, that my part and parcel of the body, this finger, so long it is fit to give service to the body, it is healthy. If it cannot give service, then it is diseased. Similarly, all living entities who are not giving, rendering any service to the Lord, they are simply working for sense gratification, that is diseased condition. And in the diseased condition, nobody can be happy. That is not possible. If you have got some disease, you cannot be happy.