Just watched "The Deadly Years," which was better than I remembered, although it still bothers me that Kirk never even considers the fact that, yes, he might not be fit to command in his condition. Kirk's stubborn refusal to admit what's happening to him is not exactly his finest hour, even allowing for his failing mental faculties.
And how come, after pretty much the entire landing party comes down with a mysterious affliction, nobody even
suggests quarantining them until they know what's causing the aging effect?
I mean, the real NASA was routinely quarantining astronauts back then, so it's not like the concept was unknown back in the 1960s . . . .