Journey to Babel is so funny because Jim knows that Spock’s father is an ambassador but it didn’t occur to him to ask Spock if he knew the Vulcan ambassador they’d be accompanying to Babel
and then McCoy literally knows the Ambassador’s age and his career history that I still have questions about
1. did they get briefed, and McCoy decided to remember everything about the Vulcan ambassador because ???
2. Sarek is such a hot shot (he is but shhh) that the rumours about his retirement reached the Enterprise? why would McCoy care to remember though? because he’s interested in Vulcans?
3. McCoy just randomly read up on the Ambassador because ???
4. did McCoy speak with other delegates about Sarek who told him?
5. was Spock like “Doctor, you’ll soon have the opportunity to meet my parents” leaving McCoy gaping after McCoy was all “who won’t talk about his background” months ago, and Spock taking it personally, so that made him pay attention?
6. or did McCoy actually ask Spock if he knew the Vulcan ambassador, and got an answer, so if they got briefed he paid attention and remembered the details?
speaking of “who won’t talk about his background”, it’s cute that in Journey to Babel Spock is like “Mother, you have my permission to tell the good doctor about my childhood” (see, Doctor, don’t pretend I never do anything nice for you)