The precise cake-eating advice comes courtesy of famed British mathematician Sir Francis Galton, who first shared his expertise on the subject in the December 1906 issue of the journal Nature.
The problem with your old man's outdated wedge slice is that it leaves the cake's inner surface area exposed to air and unprotected by icing or more cake. Thus, half of every subsequent slice will be dry and unappetizing.
To keep day-old caked sufficiently moist, Galton advised, slice a long portion from the center first. Then, push the two halves back together and secure them with a rubber band. On day three of your birthday week, slice another long center cut -- this one perpendicular to the first. The result: another two long pieces and four remaining wedges that can, once again, be pushed back into a perfect circle. The inside of the cake remains moist, forever protected from excessive oxygen exposure.
The technique was recently rediscovered by Alex Bellos, author of The Grapes of Math. He shared it with Internet viewers this week via Numberphile's YouTube channel.
"[Galton] was the king of measurement, and he was very English. He loved tea and cake," Bellos told ABC News. "He's not a household name, but so many of the things he invented are things we take for granted in the modern world."
Galton was also a big proponent of eugenics, but, moist cake may be worth taking the good with the bad.