The theme is love, particularly romantic love. We know when we are experiencing it how joyous it is. How great we feel. Perhaps one of the greatest poets who ever talked about love was Elizabeth Barret Browning who married another famous poet, Robert Browning.
She had a series of sonnets from the Portuguese on romantic love and her writings were about her great love for her husband, Robert Browning. She didn't put her attention on his physical attributes or on the material man that he was, instead she looked at all the little things which is what makes romantic love so beautiful. Her sonnets will live for thousands of years.
Written back in the 19th century, shortly before her death in 1861.
Elizabeth Barrett Browning (1806-1861)
from Sonnets from the Portuguese
How do I love thee? Let me count the ways.
I love thee to the depth and breadth and height
My soul can reach, when feeling out of sight
For the ends of Being and ideal Grace.
I love thee to the level of everyday's
Most quiet need, by sun and candlelight.
I love thee freely, as men might strive for Right;
I love thee purely, as they turn from Praise.
I love thee with the passion put to use
In my old griefs, and with my childhood's faith.
I love thee with a love I seemed to lose
With my lost saints,–I love thee with the breath,
Smiles, tears, of all my life!–and, if God choose,
I shall but love thee better after death.
Elizabeth Barret Browning speaks of her great love for her husband by talking about the passion, by talking about , not his appearances and not his material things, but the little things. She loves him with the breath and smiles and tears of all her life. So beautifully expressed and enduring. She closes with, "I shall love thee better after death" where she speaks of an eternal love rather than a temporary one.