Ever since OS X 10.7 Lion, the Finder has a new sidebar section, called All My Files. It’s a list of, predictably, all the files on your Mac and it can be customized to show them in any style you like, sorting by Name, Date Created, Kind, Date Modified, and more. The trouble is, though, that all new Finder windows open to this All My Files section by default. Some folks might not like this, though, and wish for the long-ago days of, say, Snow Leopard, when Finder windows opened to the Desktop or some such.
Luckily, to make this happen takes just a quick trip into the Finder preferences to sort out. Thanks, Apple!