Apple is well known for making hardware and software that is intuitive and easy to use, however once you take the plunge with an app like iTunes you quickly discover that to control the beast you must first memorize arcane, multi-key stroke sequences that are far from being intuitive.
For example, last night I was using iTunes to view a movie and wanted to watch in full-screen mode on my beautiful 24" external monitor. There's a little icon with opposing arrows to view full-screen, so that was intuitive to see and click:
Uh oh, now that I'm in full screen mode there is no menu to choose from, no icons to click, no visual clue on how to revert back from full screen mode. My only option was to click Command+q to quit iTunes all together, not so friendly. A quick Google search turned up the key sequence: Control+Command+F
I was expecting that some menu choice would show up when I right click in full screen mode, but nothing did. The Escape key will exit you from iTunes but not revert the screen size.
Not everything in Apple apps like iTunes is intuitive, in fact you have to memorize 3 key sequences to actually control it. There is much room for improvement here, I would suggest to Apple that in the full screen mode they add a menu when I right-click to show me how to Exit Full Screen.