split the difference
Well, I could have told you all the terms of the 20th century presidents. I'd also long known, just by way of a random bit of historic trivia, that Eisenhower was born in the Harrison administration. I knew as well the birth years of the presidents from Kennedy forward, so it was easy to correlate these with the relevant administrations. It helped to remember that Nixon was born in January, which put him under Taft rather than Wilson (presidents used to take office in March). I did have to doublecheck on Gerald Ford, whom I remembered to have been born in 1913, but whose sign I did not (Leo, with Wilson rising), and I had to consult the same almanac for the birth years of Truman back to McKinley.
I should perhaps mention that since very early childhood I have tended to maintain these internal chronologies—enough that it was remarked upon by bemused adults within a year or two of my starting school—in a freakish yet somehow endearing sort of, you know, high-functioning autistic kinda way.
cordially,
