In the 1800s, poet John Greenleaf Whittier wrote one of his most quoted poems in the English language. The poem was titled, "Maud Muller." You've never heard of it?  Actually, not many people remember this sorrowful poem, but generations of people have quoted two famous lines from its final stanza.

"Maud Muller" is about a young maiden who, while working the fields one day, sees a handsome young Judge riding by on horseback.  She offers him a drink of cool water.  Their encounter lasts only a few moments, but it makes a deep impression on both of them.  Maud is greatly attracted to the Judge, and she dreams of marrying someone of his gentleness and integrity. She could leave the fields behind and live as the wife of a wealthy and powerful man.

At the same time, the Judge is attracted to Maud.  He is tired of his career, and he dreams of marrying a warm, compassionate woman like Maud and settling into a simpler life in the country.  But neither Maud nor the Judge acknowledges their attraction to one another.  They are from different social classes - they cannot risk breaking the bonds of social conformity.

Maud later marries a man who brings her much pain and hardship. The Judge also enters into a loveless marriage.  In the final stanza of the poem, Whittier offers us this warning: "For of all sad words of tongue or pen, The saddest are these: 'It might have been!'"