i'd say , twenty to thirty is the right age to work hard and have sleep as minimum as one's physic allows, and thirty to fifty is the age to move somewhat slowly or relaxed manner and at fifty, one can get voluntarily retired to spend his time with his family and friends. many of indians who retires at sixty finds its too late to enjoy their time. instead they can retire leaving new young fresh positive and dreamy youngsters to take up a job leaving their experience and enjoy their time with family.
