Stolen from the Funny Times:

Love is like war: easy to begin but very hard to stop. H.L. Mencken

Love is the self-delusion we manufacture to justify the trouble we take to have sex. Dan Greenburg

A constant interrogation. Milan Kundera

A mutual misunderstanding. Oscar Wilde

Two minds without a single thought. Philip Barry

A grave mental disease. Plato

Love is the irresistible desire to be irresistibly desired. Robert Frost

When you're away, I'm restless, lonely,
Wretched, bored, dejected; only
Here's the rub, my darling dear,
I feel the same when you are here.
Samuel Hoffenstein

Everything we do in life is based on fear, especially love. Mel Brooks

True love is like ghosts, which everybody talks about and few have seen. La Rochefoucauld

Some women and some men seem to need each other. Gloria Steinem

In war as in love, to bring matters to a close, you must get close together. Napoleon I

If love is the answer, could you rephrase the question? Lily Tomlin

If you can stay in love for more than two years, you're ON something. Fran Lebowitz

One is very crazy when in love. Freud