First I had a plain Team Site without the Feauture "SharePoint Server Publishing" activated. I created several Site Pages, all rendered automatically without the annoying "Recently Modified".
When I activated the "SharePoint Server Publishing"-Feature all my pages now show the "Recently Modified" in the Quicklaunch. Even after Deactivating the feature, the damage is done.
What is the connection between those two things, so I can cut it off?
EDIT: Unfortunately neither do I have control over the site collection nor do I have access to the filesystem. The question is: How do I get back to the state of "not having 'Recently Modified' in my Quicklaunch" by default, (without making changes to the site collection, the filesystem or the masterpage and without Visual Studio)?