> I always get the feeling that most man pages are written for people who already know how to use the commands, rather than people new to them.

This is actually true. In some of the early Unix documentation or an interview (I can't remember which), one of the core Unix developers said pretty much this, i.e., that man pages were more like a collection of rough notes to help the developers of the Unix system itself not to forget how the commands should be invoked.