Do you know about the life cycle of the Pacific salmon? It is hatched in a little inland brook. As it grows, it begins to make its way into streams, then rivers, and finally into the Pacific Ocean. There it enjoys a wonderful life roaming the broad, powerful waves.
But for some unknown reason, one day a timer goes off in the salmon's head, and it makes its way from the ocean, to the river, to the stream, to the brook where it had been hatched. And there it dies.
They call it a homing instinct. The same instinct in the Pacific salmon exists in thousands of other creatures: pigeons, Monarch butterflies, geese, and the caribou, to mention a few.
And the same instincts are in each of us. The Good Book says it this way: "The creator has put eternity in our hearts."