Whenever I hear this question, some quotes from one of my favorite movies of all times come to mind. In Moulin Rouge, a poor poet is in love with a cynical courtesan, and when she says she couldn't fall in love, he tells her, "a life without love, that's... terrible...Love is like oxygen! Love is a many splendored thing. Love lifts us up where we belong. All you need is love!"
I watched that movie a long time ago, when I too was beginning to ponder the meaning of love, and I'll like remember those words forever. Another quote that has stuck too is when one of the characters says of love, "The greatest thing you'll ever learn is just to love and be loved in return." I totally agree. It takes courage to love, and when your love is returned, it can be beautiful.
The other exposition about love which I hold close to my heart is the one by Paul in ICorinthians 13: 4-8a
Love is patient, love is kind. It does not envy, it does not boast, it is not proud. It does not dishonor others, it is not self-seeking, it is not easily angered, it keeps no record of wrongs. Love does not delight in evil but rejoices with the truth. It always protects, always trusts, always hopes, always perseveres. Love never fails.