After pulling my hair trying to find out why my Main Sidebar disappeared, I performed as a last act of desperation a complete wipeout of the database and the entire wordpress directory, then I restored them from the earliest backup of my totally fresh install of WordPress, which includes only the home page and the original sample page and no plugins!.
That didn't help displaying the Main Sidebar.
But when I switch to
Twenty Ten, the Main Sidebar, with the calendar in it, is there!
This is insane, as I am now beginning to doubt my memory that I ever saw the Main Sidebar on
Can the Twenty Eleven theme have a Main Sidebar at all?
If so, what am I doing wrong?