There are already a bunch of posts I've found on this subreddit that talk about the subject, (like these two that really caught my eye) but it would be very interesting to ask if there's a more general, academic interpretation regarding the cultural phenomenon of "retro", or "nostalgia". In general, the inspiration and assimilation of an older "better" culture into the art and way of thinking of a newer culture. Not only in these days, where examples are plenty and we know of them (80s nostalgia in modern pop music, 50s nostalgia during the 70s, etc.), but any books or articles that talk about examples in other cultures and periods, and talk about this phenomenon in more broader terms. Maybe, for example, in the way Neoclassical architecture wanted to imitate Roman style, but how that also played into the way of thinking during the Enlightenment, just to say something. Maybe examples of how politics have been influenced by older periods that were romanticised (in this case, I can think about a generation in Mexico who lived through the 30-year dictatorship of Porfirio Díaz and after the Revolution longed for a return to those days, having important consequences in the political discourse in the country for many years after that).
I hope that what I'm asking for makes sense, and if so, I'm sure there must already be a great amount of literature regarding the subject. I really hope someone knows of some author or book that treats this topic, and I'm very much looking forward to your suggestions.
Very many thanks in advance!
So, as you mentioned, a romanticized view of ancient Greece was an important source of nostalgic longing for an idealized past that you see occurring throughout European history, especially in Italy. When this looking back took on an especially nostalgic tone, it tended to focus on a particular image: shepherds, nymphs, and satyrs frolicking about in the mythical pastures of Arcadia. The tradition of pastoral poetry extends all the way back to Virgil's Eclogues, and encompassed some of the greatest works in Italian history such as Guarini's Il pastor fido and Tasso's Aminta. In the eighteenth century, there was a whole group of literati who formed what was called the Arcadian Academy, they took on the names of mythological shepherds, created poetry, and debated matters political and artistic. Through them, the Pastoral tradition had a pretty huge influence on Eightenment thought in Italy and also on emerging romantic aesthetics (for instance, in Schiller's On Naive and Sentimental Poetry).
I know mostly about pastoral traditions through musical scholarship, which is my primary era of interest. Pastoralism not only affected poetic and artistic subjects, but there also became a characteristic sound of "shepherds relaxing carefree in the fields." Of course, this was a constructed vision of what it meant to be poor (poor = free of modern stress and more in touch with nature) that has nothing to do with the actual state of the economic poor of the day. But for a good discussion of pastoralism as it relates to musical practice, see Raymond Monelle's The Musical Topic: Hunt, Military, and Pastoral. This talks not only about the mechanisms that musicians used to invoke pastoralism (pastoral "signifiers"), but also about the cultural meaning of pastoralism in general (the pastoral "signified"), which is probably what would interest you the most.
I'm less familiar with the literature on pastoralism more generally (though the Monelle has copious references that will point you to things). But one I have read is Vernon Minor's The Death of the Baroque and the Rhetoric of Good Taste, which has a lot to say about how pastoralism intersects with the emergence of the modern notion of taste and with Enlightenment aesthetics more generally.