Just to give you an idea of how amazing this achievement is, click here to see a list of the entire works of Franz Liszt. Did you make it to the end of the page?
This is a collection of 99 discs, and this is not easy music. If each one is over an hour long, it would take you nearly a week to listen to the entire collection. You must be thinking, “This pianist must be really old to have learned that much music.” He’s not. He is 66, and this was released when he was 63.
This is certainly a lifetime of work right here, with a lot of difficult music, and that is why your argument must be invalid. 😉