"Seasons" is a wise metaphor for the movement of life, I think.

It suggests that life is neither a battlefield nor a game of chance but something infinitely richer, more promising, more real. The notion that our lives are like the eternal cycle of the seasons does not deny the struggle or the joy, the loss or the gain, the darkness or the light, but encourages us to embrace it all — and to find in all of it opportunities for growth.

Parker Palmer, From Language to Life