To be more friendly to beginners and first-time users, Opera shows a "Press Esc to exit full screen mode" notice whenever you press the F11 keyboard shortcut or choose "View > Full Screen". But this message floats and lingers in the middle of the page and slowly fades, which prevents you from reading what's below, or at least becomes annoying after a while. This tutorial explains how to permanently turn off that feature.
Open a new browser tab: type "about:config" as URL / address, and hit Enter. to load the "Preferences Editor". This page contains all customizable settings for the Opera browser!
In the "Quick find" search field, type "full" to filter the options displayed. Now uncheck the "Show Full Screen Exit Information" checkbox (checked by default), and click "Save". You can disregard the "" message - this particular option takes effect immediately. Try it by pressing F11 once to go full screen, and another to return to your normal window - no more notice!
You can close the
about:config tab and resume your browsing!