Unrequited love is a central theme of Peanuts: while Sally worships Linus, Peppermint Patty and Marcie adore Charlie Brown, Charlie Brown pines for the Little Red-Haired Girl, and Lucy LOVES Schroeder - in no case is the feeling reciprocated.

Schulz once remarked, "I don't know why there's so much unrequited love in my strip. I seem to be fascinated by unrequited love, if not obsessed by it... There's something funny about unrequited love - I suppose it's because we can all identify with it. We've all been turned down by someone we love, and it's probably the most bitter blow in life."

Unrequited love also plagued Beethoven's life. Though it was reported that he made many conquests of the heart as a young man, his love objects were frequently women who were unavailable because they were of noble birth and he was not. Noble women who married someone of a lower class lost both their nobility and rights to income from their estates. In 1804 Beethoven fell in love with a beautiful widow named Josephine von Brunswick, an accomplished pianist. Though she loved him in return, she had to renounce Beethoven because of her four children, who would have also lost their nobility and inheritances if she had followed her heart. Before she turned him down, he confided in a powerful love letter: "My heart will only - cease - to beat for you - when - it no longer beats -"

His most famous love letter was written on July 6-7, 1812, to a woman he only named as his "Immortal Beloved" in the middle of the letter. The identity of the woman remains hotly contested even today, but, in keeping with his pattern, all three leading candidates were married women in 1812. The ten-page letter is full both of passion and ambivalence: "Can our love exist but by sacrifices, by not demanding everything... I can only live either wholly with you or not at all, yes, I have resolved to stray about in the distance, until I can fly into your arms and can call myself entirely at home with you... never can another own my heart, never- never -... at my age I would need conformity regularity of life - can this exist in our relationship?" The letter closes with passion: "today -yesterday - What tearful longing for you - you - you - my life - my all - farewell - o continue to love me-"