I read Pushkin again today. Alexander Sergeyevich Pushkin, greatest of all Russian poet.
This one is actually untitled and translated version- I cant read Russian after all, about love. Well, the man himself died in duel because of his wife relationship. Ah its kinda hard to have pretty wife I guess.

I loved you and my love I think was stronger
Than to be quite extinct within me yet.
But let it not distress you any longer,
I wouldn't have you feel the least regret.
I loved you bare of hope and of expression
With turns of jealousy and shyness sore.
I loved you with such purity , such passion
As may God grant you to be loved once more.

Why do people fall in love? According to Herman Hupfeld in As Time Goes By:

Moonlight and love songs
Never out of date.
Hearts full of passion
Jealousy and hate.
Woman needs man
And man must have his mate
That no one can deny.

Some folk at the LBGT might disagree with the song though,
but to each on their own I would say. With that saying~
Let us all live and love again and again.