Robert Crawford - Experience.

Experience is a stern pace-maker, and
'Tis on the road to wisdom, that rough way,
So many fall.
Wrongs unrepented and unpunished breed
More deadly growths of that pernicious seed.
Were all men equal, were all dull or keen,
Ulysses or Ajax had never been.
Even as men shut their doors to unkind airs.
Misery in poverty unpitied fares.
I hate effeminate men, she frowning cried;
And I a mannish woman, he replied.
The one white violet's the innocence
A maid knows not she had — until it's gone.
An unclean thought still like an ulcer eats
The life immortal.
Life at the best is what it makes of hope;
Its use or its abuse is all.
Our sweet sins have their own sour medicine,
And that must cure us.

Robert Crawford

http://www.poemhunter.com/poem/experience-28/