[B]ecause the second time I ever saw you I learned what I had read in books but I never had actually believed: that love and suffering are the same thing and that the value of love is the sum of what you have to pay for it and anytime you get it cheap you have cheated yourself.

He learned that love is not all pleasure, but can be agony and heartache, martyrdom and sacrifice. He learned what the clergyman was talking about in the marriage service: for better for worse, for richer for poorer, in sickness and in health, to love and to cherish till death do us part.

Only two things can reveal life's great secrets: suffering and love.

He just thought quietly, 'So this is love. I see, I was wrong about it too', thinking as he had thought before and would think again and as every other man has thought: how false the most profound book turns out to be when applied to life. [...] 'Perhaps they were right in putting love into books,' he thought quietly. 'Perhaps it could not live anywhere else.

To love is to suffer. To avoid suffering, one must not love. But, then one suffers from not loving. Therefore, to love is to suffer, not to love is to suffer, to suffer is to suffer. To be happy is to love, to be happy, then, is to suffer, but suffering makes one unhappy, therefore, to be unhappy one must love, or love to suffer, or suffer from too much happiness — I hope you're getting this down.

From her he had learned two fundamental things about love: first, that unlike what the romantics so pompously argued, love was more a gradual course than a sudden blossoming at first sight, and second, that he was capable of loving.

I had seen the struggle to love and make one's self understood, the refusal of two persons in conversation to give themselves to each other, the coming together of two lovers, the lovers with an infectious smile, who are lovers in name only, who bury themselves in kisses, who press wound to wound to cure themselves, between whom there is really no attachment, and who, in spite of their ecstasy deriving light from shadow, are strangers as much as the sun and the moon are strangers.

To love is to suffer and there can be no love otherwise.

To love is to suffer. To avoid suffering one must not love. But then one suffers from not loving. Therefore, to love is to suffer; not to love is to suffer; to suffer is to suffer. To be happy is to love. To be happy, then, is to suffer, but suffering makes one unhappy. Therefore, to be happy one must love or love to suffer or suffer from too much happiness.