About a month ago I was studying LLMs and downloaded a video on how to make ChatGPT2 from scratch – then forgot about it. On my Pixel Android I use Google Feed and this will obviously include stories related to the topics I browse.
I stopped LLM research a month ago due to other pressing tasks.
On a long plane trip, I had no connectivity and was browsing my videos when I saw this one had been stored. I watched it for about 30 minutes and then moved to other things.

When I got back online the lead item in my feed was a different video with almost the same title – How to make ChatGPT2 from scratch. The chance of this being a coincidence is quite low.

My question is does google track your offline activity such as what files you open? Did it identify the topic from the audio stream?
This is activity that users would think is private, but it is hard to keep track. When did this capability creep in? Hence this question.