My son. It's tanks. He's 12 and can go on for hours about them, rattling off their armor thickness (in mm), caliber of their guns, horsepower of their engines, declination and traverse speeds of their turrets, etc. I took him to a tank museum one time, and no shit a quarter mile from the museum he sees the tank out front and he goes: "That's a Sherman M4A4!!" Ten minutes later we're parked and walking up to the museum, I look at the tiny info placard, M4A4, think to myself: "What the fuck."

I forget my own fucking birthday but let me wax poetically about extinct Australian megafauna for a few hours.

Though it's episodic memory, if you ask me to give you a fun fact, let alone name a species just off the cuff, my mind goes blank. I don't know anything about anything.

But give me a minute to set myself the mental stage and start rambling about how as a kid I was obsessed with this old faux taxidermy at the Melbourne museum because it was like a derpy wombat horse. One time my mum took me to a kids activity workshop where we got to pretend we were digging up fossils and analysing them... did you know Australias geologic layering contains every single rock type that exists in on earth. Lots of Australian fossils are found in soft limestone. Hang on, dippy don! That's what I named the derpy wombat at the museum. It was a Diprotodon, a herbivorous marsupial who died out about 40,000 years ago. The cave in NSW where they found a bunch of specimens was 400 million year old limestone but Dippy only entered the record ~2 million years ago, so it suggests they burrowed, which makes sense when you look at their closest living relative, the wombat, though Diprotodon and the family it belongs to is a dead end on the evolutionary tree.

But yeah, you can't always rely on where you find the bones to date the specimens which is why carbon and uranium dating really changed our understanding of Australian history.

Speaking of locations of fossils, diprotodon is one of the only known Australian marsupials to seasonally migrate, so their range was huge! So were they! 2m tall, 3m long and easily 2500kg heavy, and have two giant protruding teeth (hence their name Diprotodon, Greek for "two protruding teeth", Di=two, pro to/protrude, don/dontics like orthodontics ....I also like etymology) and lived in the marshlands. European archaeologists thought they were originally skeletons of some kind of hippopotamus, but several mobs of indigenous Australians had/have oral histories around diprotodon. the last living dipro's died out after the first Australian peoples inhabited the land. Which is why there is an association between dippy and bunyip (an Australian cryptid/aboriginal mythology) a giant melevolent monster who haunts billabongs.

They indigenous Australians are often blamed for the extinction of a lot of megafauna, there was a theory of overhunting for the many years, but to date no diprotodon fossils have been found with evidence of human butchery, but we do have evidence that people would move bones around for some reason.

Anyway....

It's like a trance, and it's really hard to stop once you start, but you can't just pick up into it, something has to trigger the memory to surface, like seeing a certain train go past to remember specific train facts, or in my case thinking about where you I was and who I was with when I first learned some of the best facts about my thing.

Though I have AuDHD so not sure if the episodic memory is my autism or my ADHD, it feels like ADHD because the thoughts are so bouncy when they come, but it also feels like like autism because it's anxiously obsessive in a fun way inside my brain once they journey starts.

Also maybe remembering cool megafauna facts is why I forget things I should remember like what house number I live at or what year I was born (genuinely forgot these things, had to go to the front of my house to check, and do maths because I could remember my mums birthday and how old she was when she had me, but not my own birthday or age .... Autism and memory is fucking weird)