Page Security

I passworded a page. When I enter the site through the web and go to this particular page, I see the login. I enter the password and see the contents. However, navigating away from the page and going back later on, the page contents are visible. Is this normal? Should it not close upon navigating away from the page and require a new login?

See:http://www.ve3erc.ca/name-call-sign-2/

Thanks
JB