Huge Headcanon — Mind Palace
Yao has an excellent memory with relatively few faults considering how long he has lived. With amazing fluency and memorisation capabilities, it’s something of a wonder that he can actually internalise information still.
It just so happens that a few thousand years ago, he found the perfect system: a mind palace.
Also known as the method of loci, a mind palace is a type of mnemonic accredited to Simonides of ancient Greece. It involves memorising the layout of a building or an arrangement of shops or really anything with specific loci, and then visualising and mentally navigating this map in order to find information.
Naturally, a lot of people will snap to this:
But I’m actually being kind of serious.
This reminds me a bit of the Gate of Truth from FMA too.