She needed him as the moon needs the sun.

His kindness warmed her soul when she was in need of a friend, someone to rely on, to confide in. Shiny brilliantly bright, she grew to her highest potential through his constructively critical comments, his occasional smiles helping her along the road to ultimate personal greatness. They were wonderful, together.

But apart they were weak, fragile, easily hurt and influenced by those who wished them harm. At times when they were apart, he haunted her thoughts, her dreams. Her horribly constant dependence on her beloved drove her into near madness. He pulled away from her words of commitment, her cries of painfully needy love for him; as she drew nearer, he pulled away, farther and farther until only memories remained of their fleeting romance.

Eventually, they both moved on, although they would never forget one another.
He remained in her heart as she remained in his.

No one ever really falls out of love.