How do I prevent my mac's wifi from ever (not just once) seeing a particular wifi network?
What about something even easier? There's a great app for OS X called Concentrate that will block distractions for you for periods of time. In particular it'll block your access to apps when you want to focus so you can stop surfing Ask Different when you should be studying. Have it block Chrome, Safari and Firefox and any other apps you find distracting and you might find that's easier than trying to have WiFi but not have your computer connect to it.