Love is a smoke made with the fumes of sighs;
Being purged, a fire sparkling in lovers' eyes;
Being vexed, a sea nourished with lovers' tears;
What is it else? A madness most discreet,
A choking gall, and a preserving sweet.
Love is not love which alters when it alteration finds.
They do not love that do not show their love.
The courses of true love never did run smooth.
-- William Shakespeare