We need to clarify three things: what is
love; what is
romantic love; what is a
meme. I
don't intend to tackle any of these in detail here, this is just passing thoughts.
Love, (as opposed to the cultural trappings inherent in the presumption that romantic love is something different) is of course fundamentally biological, and we could go to chimpanzees and bonobos here, but I'd rather not. Nor do I know any ethnographic studies of how far-flung peoples experience love (we'll draw a veil over Margaret Mead). Obviously bonding going with sexual pleasure has had a powerful effect in our evolutionary history, and it manifests itself as the feeling of love.
Or rather, three feelings. You can (to some extent) separate out three biological components: of course, often they co-occur and are intermingled. Some hormones, like testosterone and IIRC oestrogen regulate the sex drive, or lust. Others, like serotonin, keep us in a happy mood when we're with the beloved and make us pine to be with them when we're not. Then vasopressin and oxytocin create a feeling of unity, bonding, bliss: they also occur in childbirth and in orgasm.
The original poster, alex.tan, repeated the idea that romantic love was a relatively new idea in human society, a few centuries old. (BTW, at the time I write, there is no node for romantic love as such, so it's up for grabs.) This is a common... yes, I'll say it, a common misperception. Or misunderstanding, perhaps better. The name of 'romantic' is mediaeval in origin. The troubadours and trouvères and Minnesinger from about 1100 sang tales of King Arthur and his court, of fair ladies and noble knights. This was a new genre of story, and its invention may be attributed to them, recent in human history.
(Digression. It was called Romantic because it was in the language of the Roman Empire: but not the learned version used by scholars and clerks, but the vernacular spoken across the Roman Empire: Italy, Gaul, Spain. By this date these vernacular dialects had diverged so much from the original Latin of a thousand years previously, and indeed from each other, that they were what we now recognize as separate languages: Old French, Old Provençal, Old Spanish, Old Italian. However, they didn't know that then, and they called the popular language Roman. A tale told in Roman was called a romance.)
If you expect your love life to contain knights in shining armour, see The myth of romantic love. But I don't think many of us do. Not on E2 anyway, us elite :-P
Love, passionate, consuming love that makes you ache and carve your beloved's name on trees and pine away and go into fits of anger and misery, that sort of love that we all do know, has an older pedigree.
In the Golden Age of Latin, the time of Caesar and Virgil, the love poem in the modern sense, with all that we recognize in ourselves, was being invented by Catullus. His mistress was Clodia Pulchra, whom he called Lesbia in his works, and she led him a merry dance, as no doubt he did her, but that was as romantic as you could wish. We haven't worked out much more about it than Catullus and Lesbia knew and felt.
(Tom Stoppard's recent play The Invention of Love is about A.E. Housman, the scholar who worked on Catullus's fellow love elegist Propertius. He has Housman say that Catullus actually invented them: the specific form of poetry, the elegy, though certainly not the feeling. The love poem had to be invented, like the magnetic compass and the fountain pen, before anyone could use it, and Catullus was the one who did that.)
Catullus's poetic inspiration was Sappho, greatest of all lyric poets, creator of the most beautiful and sensuous poetry of all time: read To a Young Girl and be ravished.
A meme is an idea whose manifestation helps cause it to be reproduced. If you see someone else in love, a young couple swinging each other around in a park, gazing enraptured into each other's eyes… all that guff… do you ever think it might be nice to have that? If so, to that extent love is memetic.