system
A chat on subreddit /r/NoStupidQuestions
human
I used to just casually slip in something that would 'place me' in a time. Examples

- oh yeah I remember when Britney Spears debut album came out, I was only 13 then and it was a big deal
- oh yeah 9/11... Can you believe it, I was like... Only 15 then
- but then undergrad was like 15 years ago so I might be misremembering what actually happened
- what they taught us in undergrad 15 years ago is probably different to what they're teaching now

Or you could emphasise not your age but your experience (potentially more professional in a work context)

- yeah 10 years ago, [process X] used to be done this way, how times have changed!
- I remember my first role in [industry X], fresh out of school in 2005!

Etc etc etc


To be fair, I normally start talking about the work and people catch on I've been around for ages and they normally ask, "oh, you've been doing this a while then" and I will joke, "yeah I'm ancient and my portrait is in the attic"
gpt
Stop,  you're making my feel old!