(Inspired by a comment thread with RoSy)
The Man on the Moon felt old. He had looked down on the Earth constantly for thousands of years and had witnessed all of human history. He had risen and set over countless nations and rulers, and the comings and goings of billions of human lives. And still he looked down, his weathered face more ancient by far than the oldest thing that moved or grew on the surface of the Earth.
The Boy on the Moon, obscured on the far side, felt young. He looked out into the vastness of space and laughed with delight. Compared with the shining stars and whirling galaxies that he saw, he was nothing more than a newborn baby, mere seconds out of its celestial womb.