"Your Penelope cannot have waited longer nor with more eager expectation for her Ulysses than I did for you." (Petrarch)
Doubtless if any of us readers would jump at the opportunity to become close-correspondents with our favorite writers, but only Petrarch would do so one-sidedly and yet still come across as admiring and teasing at the same time. Petrarch brought writers back to life by calling attention to their influence.
It takes an incredibly empathetic perspective to see the intent beyond the writing of long-dead, almost-legend authors such as Homer and Cicero, and yet he was capable of addressing the human creator beyond their works, knowing that obscurity would be their greatest fear. After all it is a fear that Petrarch himself relates to as seen in the concluding lines of his letter to Homer when he seems mournful despite how freely Homer has spoken to Petrarch, Homer will never receive or care to read Petrarch's observations.
The common theme throughout his letters is pointing out how much Petrarch's contemporaries owe to these early writers. He frequently mentions that although they may not be mentioned by name, it is impossible to overlook their obvious influence. He is constantly, although teasingly, soothing their egos by pointing out that time has not silenced their works.
But in his letter to Castiglionchio, regarding the importance of saving older works from obscurity, raises an issue central to the Ad Fontes spirit of the Renaissance, which is to say that true knowledge is timeless and unaffected by change. Revelations of the past are just as important and beautiful in the modern day.
He also, of course, takes a moment to taunt his author correspondents. Of course.