If you use an Android phone, YouTube, Google Search, Google Maps and other Google products, chances are Google has more data on you than you could imagine on "Google My Activity."
Google knows what searches you've done, websites you're visited, YouTube videos you've watched, what you've voice searched for and where you've been (if you use an Android phone).
Let's take a closer look at myactivity.google.com.
Today I was at the local vernal pond at Rancho Sierra Vista/Satwiwa with my son to look at the tadpoles and frogs. My son found saw a group of tadpoles acting out The Walking Dead by apparently feasting on a dead tadpole. At his urging, I pulled out my phone and tapped the Google Voice Search icon and said "do tadpoles eat other tadpoles." And sure enough, My Activity showed that I did search for it and provided a recording of my query.
Now if you forget where you were some day and are looking for a reminder, My Activity can help you with that too. Simply click Other Google Activity then under Location History click Visit Timeline. I clicked this and "today" and saw a map of everywhere I went today while carrying my phone. Kind of creepy actually. But also potentially useful...where was I on Christmas Day 2015? Searching My Activity turned up the fact that we were actually in the Florida Keys.
I took a look at activity prior to January 1, 2015 to see what Google had on me and it showed all my YouTube activity, including searches and videos watched.
Some folks may get a grin out of reviewing their activity. I apparently was helping my kid with geometry homework on April 13, 2016:
So the good news is that if you don't want Google stockpiling all of this data you can do something about it. Click "Activity controls" where you can manage the tracking of your web and app activity, location history, device information, voice and audio activity and YouTube search history You can also go to "Delete activity by" and remove any or all of what has been recorded.