I'm really the only one in my household that knows how to use it.
Here's a solution that would work well with system of multiple-level access control modes mentioned
here and described
here. An annoying idiot-tip could be displayed on every use of the OSD until a user at that level used the OSD to turn it off.
But seriously, this is part of the reason why I think a dual-mode single-line/full menu system would be so helpful. Unfamiliar users could use the full mode and see a menu tree of all commands and settings. That would guide them to whatever it is they need to do (e.g., first,
discovering there are applicable subtitle settings, and
then choosing the one they need). But they would quickly learn all the same things are available in the single-line mode, and that's the best way to quickly access one item without disrupting the viewing of the video. Experienced users would use the mode that works best in the circumstances (e.g., using the full mode to review all settings at a glance during the opening credits).