OK let me get this straight.

Google is smart enough to track every click and behavior (and location tracking too) of billions of Android and website users.

Google is smart enough to create a comprehensive dossier of your behavior and sell it to advertisers.

But Google is NOT smart enough to figure out that I am over 18.

Even though I explicitly told Google I am an adult.

Even though my YouTube watch history is almost exclusively software engineering and Linux videos.

And I have a GitHub account.

... it was the PewDiePie Linux video, wasn't it?