In theory one is aware that the earth revolves, but in practice one does not perceive it, the ground upon which one treads seems not to move, and one can live undisturbed. So it is with Time in one's life.

I didn't used to wear a watch. Now I have a SPOT watch, which I wear all the time.

While I thought that I was learning how to live, I have been learning how to die.

Because I could not stop for death, He kindly stopped for me; The carriage held but just ourselves and immortality.

They must often change, who would be constant in happiness or wisdom.