Me neither, but I guess the tracking will also take place when you just browse the internet and visit websites, that have Google Ad Tracking technologies implemented (which could be the majority of websites). Tracking and Ad-Blockers like uBlock might help a bit, though.

The specifics are complex—these are the algorithms that ingest all the data signals you give off when browsing the internet on any device, some based on who you are—device, IP and credential identifiers, but also the sites you visit and apps you use as a map to be followed and analyzed.