The good news is you can try as many times as you want without your phone going into disable mode. If you simply can't remember the code you used, you don't retrieve it. You have to restore your phone, meaning you'll follow the directions in this link. You'll have to wipe your phone down to factory fresh and then restore it. Next time, write the code down somewhere where you can easily access it again.
Even though is for how to reset your phone from not remembering your phone passcode, the steps are the same for a forgotten restrictions passcode. Sorry, but this is not quick or easy.