"Consider a deer wandering in the garden. It has found a mate and the garden is full of green grass on which it can live for its entire lifetime. The flowers growing there and the gentle breeze wafting across the garden make the deer so happy that the thinks there is nothing which can ever spoil his bliss and his contented life there. But all the while, the dread wolf which is bent in eating it up, is standing there, in front of it. In its preoccupation with its mate and the beauty of the garden, the heavenly taste of grass, and the wonderful breeze which is blowing across the garden, the poor deer does not see the wolf. Nor is it aware of a hunter who is even now aiming his dread arrows at it from behind. Man's life on earth is even like that of the unfortunate, careless deer.
"The pleasures of the world are as evanescent as the scent of the flowers in the garden. Man and woman wander around in this little garden in search of the fleeting pleasure found in each other. All the while, Time, in the form of a wolf, is waiting there in front of him and he does not notice it. Behind him is Death with a thousand diseases in the form of arrows. He sends the arrows one by one and yet man does not understand the message - does not heed the warning."
-Narad, in the Srimad Bhagavatam