He, of course, could not grasp what that was, but I explained it is a disease that was making things difficult for him to do [what] he had always found easy, and was also making him forget things.
Tema muidugi ei suutnud mõista, mis see on, kuid ma seletasin, et see on haigus, mille tõttu tal on raske teha seda, mis varem nii kerge tundus, haigus, mille tõttu ta kipub unustama.