What’s the oldest piece of technology you still use?

Paper, introduced ~25 A.D. https://en.wikipedia.org/wiki/History_of_paper

2001 Ford Escort ZX2. Manual transmission, manual locks, no firmware or spyware, no chance the entertainment system can be hacked to remotely disable the brakes. It has a tape deck FFS.

Fire, a few times a day. It's quite useful.

Or do you mean 'oldest technological artifact' you still use? I have a banjo that was made in 1895. Not techy enough for you? Maybe a c. 1960 waffle iron? An old cast-iron skillet?

Emacs. ftp. bash.

I have a computer game, copyright 1996 (IIRC). I played it last night.

Some of my dinner plates are 30 years old.

I have a pocket knife that was my grandfather's. I don't actually use it, though.

Regularly : A blade

Every once in a while: A rock to smash something

Rarely : fire

Rock, used as hammer, knife sharpener, knife, scraper, particle weapon, etc.

Do I win? Anyone got a tool older than rocks?

True IBM clicky keyboard. ~1995. Made in USA.

hammer, early model was called a rock.

Late 1970's radio

Electromagnetism

Glazed pottery

Electricity

Myself

Brain.

fork

the adze

the wheel.