A backlog item is a topic that I’d like to spend more quality time on but can’t at the moment. You’ll be able to find backlog items in the backlog list. See the menu in the upper right.
In his book The Better Angels of Our Nature: Why Violence Has Declined [Hardcover]  (Author) Steven Pinker, Steven Pinker writes about how no matter how bad we think times are it used to be worse.
This interacts with some of what I’ve heard in the wonderful podcast Hardcore History.