Pliny, Natural History 7.88:
“It would hardly be easy to say who possessed the most outstanding memory, that most necessary benefit in life, because so many people have achieved glory in that arena. The king Cyrus could give the names of all the soldiers in his army, while Lucius Scipio could name everyone among the Roman people, while Cineas, the ambassador of king Pyrrhus, knew the names of everyone in the senate and the equestrian order the day after he had come to Rome. Mithridates, the king of twenty-two nations, gave laws in just as many languages, and spoke them individually in the assembly without any interpreter. A certain Charmadas in Greece could name the authors of any book ever written as though he were reading them right then.
The art of memory was finally contrived and discovered by the lyric poet Simonides, and brought to perfection by Metrodorus of Scepsis, such that anything which was heard could be repeated in the very same words. Yet there is nothing in humans which is as fragile as memory: it experiences the injuries and fears of disease and accidents, sometimes in particular, and sometimes entirely. One who was struck by a stone forgot just his letters; yet one who fell from a tall roof forgot his mother, neighbors, and relations. One sick man forgot his slaves, and the orator Messala Corvinus even forgot his own name. And so, often the memory in a relaxed yet healthy body tends to fail. It is also cut off by the approach of sleep, such that the relaxed mind wonders where it is.”
Memoria necessarium maxime vitae bonum cui praecipua fuerit, haut facile dictu est, tam multis eius gloriam adeptis. Cyrus rex omnibus in exercitu suo militibus nomina reddidit, L. Scipio populo Romano, Cineas Pyrrhi regis legatus senatui et equestri ordini Romae postero die quam advenerat. Mithridates, duarum et viginti gentium rex, totidem linguis iura dixit, pro contione singulas sine interprete adfatus. C<h>armadas quidem in Graecia quae quis exegerat volumina in bibliothecis legentis modo repraesentavit. ars postremo eius rei facta et inventa est a Simonide melico, consummata a Metrodoro Scepsio, ut nihil non isdem verbis redderetur auditum. nec aliud est aeque fragile in homine: morborum et casus iniuria<s> atque etiam metus sentit, alias particulatim, alias universa. ictus lapide oblitus est litter<a>s tantum; ex praealto tecto lapsus matris et adfinium propinquorumque cepit oblivionem, alius aegrotus servorum, etiam sui vero nominis Messala Corvinus orator. itaque saepe deficere temptat ac meditatur vel quieto corpore et valido. somno quoque serpente amputatur, ut inanis mens quaerat ubi sit loci.