At the age of ten, he is a child; at twenty, a youth, and at thirty, he is called handsome. At forty, he is full of life; at fifty, his foot slips, and at sixty, old age is upon him. At seventy, he loses his intellect, and at eighty, he cannot perform his duties. At ninety, he lies in his bed, and he cannot understand his weakness. After seeking and searching for such a long time, O Nanak, I have seen that the world is just a mansion of smoke. Granth Sahib