Facebook stores almost every single interaction you've had with the social network since you joined, including every time you've logged in, ads you've clicked, events you've been invited to, a list of the people you follow, your friends, your hometown, every time you've sent or received a message, every single status update and more.
It's basically the history of everything you've done on Facebook. It's also the data that Facebook can use to learn more about you. When others get unauthorized access to this data, they can learn a lot about you as well, as we learned from the Cambridge Analytica scandal that's currently unfolding.
Here's how to see everything Facebook knows about you and how to download your own archive of that information. It might be useful, especially if you're planning to quit and take some of those memories with you.
To learn what Facebook has on you, check out this page titled "Accessing Your Facebook Data." The above image is just a sample of what's there.
It's kind of surprising how much data is there, but it includes everything from check-ins to chat conversations, credit card numbers you've saved, phone numbers, photos and more.
When I did this, I found conversations with individuals I had years ago, photos from my timeline, ads that I had clicked throughout the time I've been using Facebook, groups I'm in, posts to my timeline dating back to 2005 and more. It even had events that I was invited to or attended back in college in 2006.
You can download your own archive of this data from Facebook. Here's how:
Again, what you'll find is that this is an entire history of your life on Facebook.
You can use this as a copy of your profile that you can download if you plan to leave the social network, but it's also just a reminder of how much Facebook knows about you.