I happened on it by accident actually.
Rather than clicking the maximize button in the upper right, I manually resized the window all the way out and then exited the browser. When I reopened the browser it came up that way. It appears to work both ways. If I manually make the window smaller and exit, it will still be the size that I left it at when I come back in.
For some reason, however, it does not happen every time I try it.
Weird
I notice that I have an option to delete my post now too. Thanks to whoever set that up for me.