Should we believe Boncompagno da Signa (1170-1250), scholar and professor of rhetoric at Bologna and Padua, when he says that he was able to memorize the names of five hundred of his students in only thirty days?
Through the natural gift of memory and by visualising the letters of the alphabet, I committed to memory the names of five hundred students in thirty days. I recall something which seemed even more astonishing, namely that I addressed each of them in public by their own name, without omitting their surnames or the place where they were from, which struck each and everyone with admiration.
“Per illam siquidem imaginationem alphabeti, memorie naturalis beneficio preeunte, in XXX diebus quingentorum scholarium nomina memorie commendavi. Refero etiam, quod mirabilius videbatur, quia unumquemque nomine proprio, non omissa denominatione cognominis vel agnominis et specialis terre de qua erat, in conspectu omnium appellabam: unde cuncti et singuli admiratione stupebant.”
Rhetorica novissima, ed. Augusto Gaudenzi, in ‘Scripta anecdota glossatorum’, ed. Augusto Gaudenzi, 3 vols. Biblioteca iuridica medii aevi (Bologna, 1888–1901), 2:279. The loose translation is my own.
I think there may be more hyperbole than plain fact here. It’s very unlikely that he would have met, let alone converse with so many students in such a short period of time. Besides, as a rhetorician, Boncompagno was a more faithful companion of colores rhetorici (rhetorical devices) than of factual truth. On the other hand, he seems to have had a successful career as a teacher, so whether or not he had an elephantine memory, he surely knew how to market his flair.