Long before the Internet was something everyone uses, I worked in the direct mail marketing (junk mail) industry. That creepy line was crossed when the first credit cards were issued and someone figured out that they could take the sale and user data to create demographic profiles. Even if you never used the Internet and had no cell phone, you can be easily tracked. So unless you use cash only, never use a store loyalty card, and live entirely off the grid, there is tons of data out there about you that you have no control over. They know what you buy, where you buy it, how often you buy it, where you live, your age, sex, probable health issues, your phone #, rough income, what industry you work in, etc. Far more than most people realize.
And even if are able to hide yourself from Google, every router and every ISP your traffic goes through leaves a trail of where you've been.