What medical condition does leonard suffer from in memento?

Anterograde Amnesia

Explanation:

Leonard suffers from what is known as anterograde amnesia. Anterograde amnesia is a selective memory deficit resulting from brain injury in which the individual is severely impaired in learning new information

because it's a cool name

explanation:

moon-letters were a method of writing invented by the dwarves. moon-letters were ordinary runes, but written in such a way that they could only be read when the light of the moon shone behind the writing. some moon-letters could be read by any moonlight, but it was possible to make the writing even more secret. more sophisticated moon-letters could only be read by the light of the same shape of moon, or at the same time of year, as when they were written. hope this !