Goethe's departure for Italy, in 1786, took place in greatest secrecy, of which some of his closest confidantes (Charlotte von Stein, among them) learned only after the fact. Goethe's father had traveled in Italy after his studies and later impressed on his son his own enthusiasms. Goethe went to Weimar when he was twenty-six and spent the next ten years immersed in administrative duties, while his literary efforts took a back seat. He seemed to become a different person, leaving all his youthful enthusiasms behind. When he finally made the trip to Italy, he was almost forty years old. It seemed to be now or never. As the detail from the above painting conveys, enthusiasm for Italy encompassed a lot of people in the 18th century.
To a scholar of Goethe, an interesting aspect is how little Goethe devotes to describing Italians or Italian customs. If you want to know about plants, minerals, rocks, architecture, monuments, and so on, Goethe is your man, though much of what he includes in his letters and later accounts (e.g,, Italian Journey) is artfully constructed rather than representing a spontaneous travel account. He mentions, for instance, meals taken, but he never discusses the characteristics of Italian cooking. A good contrast are the books of Friederike Brun, who traveled in Italy a decade after Goethe but whose Italian portraits were published before Italian Journey. Goethe had access to her books, and, though I have not yet investigated it, I think he was probably guided by her to some extent. (Like Goethe, she was also unnerved by the Roman Carnival.)
Thus, I enjoyed a recent exhibition of "vedute" and "capricci" at the Metropolitan Museum of Art: Italy Observed: Views and Souvenirs, 1706-1899. "Vedute," meaning views, are essentially topographical, while capricci are much more fanciful and idealized. The vedute portray those aspects of everyday life that Goethe seemed to ignore, like the scene above of a beggar outside a colonnade, drawn by Francesco Guardi ca. 1780-90, thus the very period when Goethe was in Rome. He even fails to mention that one could purchase souvenirs of the sites, e.g., the fan below with an image from the excavations at Herculaneum and Pompeii, from the same period. We go to Goethe to learn other things.