My favorite...
"Nothing Gold Can Stay"
Nature's first green is gold,
Her hardest hue to hold.
Her early leaf's a flower,
But only so an hour.
Then leaf subsides to leaf,
So Eden sank to grief.
So dawn goes down to day,
Nothing gold can stay.
-Robert Frost
It's really only recently that I'm realizing what an absolute truth this is.
And I think I can almost finally accept it...