“Nothing gold can stay.” It’s my favorite line from my favorite poem by my favorite poet.

“Nature’s first green is gold,” wrote Robert Frost, yet it’s “her hardest hue to hold.” And while “her early leaf’s a flower,” it’s “only so an hour.”

The poet was describing what philosophers call the law of mutability, what scientists call the second law of thermodynamics, and what Judeo-Christian theologians attribute to The Fall. Nothing stays the same. Eventually, all things run down. Only heaven is forever.

Some days, I wish I could go on teaching these students, in these classes, at this college forever. But, put simply, that option is not open.

The thought helps when I’m feeling guilty about leaving such a cherished place. If not this year, then the next or the next because—on this fallen planet—

Nothing gold can stay.