Life means tension, effort. Only death is relaxed. So whenever a person becomes absolutely relaxed, he is both - alive outwardly and dead within. You can see in the face of a Buddha both life and death simultaneously that is why there is so much silence and calm, they are part of death. Life is not relaxation. You relax in the night when you are asleep That is why the old traditions say that death and sleep are similar. Sleep is a temporary death and death is permanent sleep. That is why night relaxes you, it is the outgoing breath. The morning is the incoming breath. The day makes you tense and the night relaxes you. Light makes you tense darkness relaxes you. That is why you cannot sleep when there is light, it is difficult to relax because light is similar to life, it is anti death. Darkness is similar to death it is pro death.
So darkness has deep relaxation in it, and those who are afraid of darkness cannot relax. It is impossible, because every relaxation is dark. And darkness sounds your life on both the sides. Before you are born you are in darkness; when life seizes you are again in darkness. Darkness is infinite, and this light and this life are just a moment in it, just a wave arising and then falling back. If you can remember the darkness that surrounds both the ends, you will be relaxed here and now.
Life, death - they are two sides of existence. The incoming breath is life and outgoing breath is death. So it is not that you die someday, you are dying with every breath. That is why the hindus have been counting life in breaths, they do not count life in years. Tantra, Yoga, all the old Indian systems, they count life in breaths, how many breaths you are going to live. So they say if you breathe very fast, with too much breathing in a short time you will die very soon. If you breathe very slowly and your breaths are less in an interval, you will live very long.
And this is so. If you go and observe animals, those animals whose breathing is very slow live long. Take the elephant, the elephant lives long, the breath is very slow. Then there is a dog, the dog dies soon, the breath is very fast. Whenever you find an animal in which the breath is fast, any animal, that animal will not have a long life. A long life is always with slow breath.