One has to examine the question of death and old age, and it is only possible to examine when there is no fear of death. One uses the physical organism mostly wrongly, with great deal of strain. The organism is like a perfectly running watch or an exquisite mechanical instrument, and it must run smoothly. If you get sand in it, it soon wears it out. To keep the organism functioning properly, one has to eat rightly, have no conflict, physically or inwardly. Conflict is like putting sand in a watch: it will stop. Emotional excitements are also contributory factors for the declinine of the mind in old age. Another much more complex factor is the understanding of the fact of death; the organism coming to an end.