Watching them grow
There is nothing in the world more fascinating than watching a child grow and develop. At first you think of it as just a matter of growing bigger. Then, as the infant begins to do things, you may think of it as "learning tricks". But its more complicated and full of meaning than that. The development of each child retraces the whole history of the human race, physically and spiritually, step by step.
Babies start off in the womb as a single tiny cell, just the way the first living thing appeared in the ocean. Weeks later, as they lie in the amniotic fluid in the womb, they have gills like fish. Toward the end of the first year of life, when they learn to clamber to their feet, they're celebrating that period millions of years ago when our ancestors got up off all fours. It's just at that time that babies are learning to use their fingers with skill and delicacy. Our ancestors stood up because they had found more useful things to do with their hands than walking on them.