Lao Tsu says the way of life is ancient, timeless. It is existence which he calls the Tao - a mysterious source, beyond understanding, and all of us are a reflection, if not that source of life ourselves.
This is what Zen means by being detached—not being without emotion or feeling, but being one in whom feeling is not sticky or blocked, and through whom the experiences of the world pass like the reflections of birds flying over water.