The uses of sorrow I comprehend
Better and better at each year’s end.

Deeper and deeper I seem to see
Why and wherefore it has to be

Only after the dark, wet days
Do we fully rejoice in the sun’s bright rays.

Sweeter the crust tastes after the fast
Than the sated gourmand’s finest repast.

The faintest cheer sounds never amiss
To the actor who once has heard a hiss.

To one who the sadness of freedom knows,
Light seem the fetters love may impose.

And he who has dwelt with his heart alone,
Hears all the music in friendship’s tone.

So better and better I comprehend,
How sorrow ever would be our friend.

Ella Wheeler Wilcox

http://www.poemhunter.com/poem/sorrow-s-uses/