Something I still haven't got is the difference between OOP and simply using objects.
It's blurry, since different people consider OOP different things. Generally though, Object Oriented Programming isn't programming, it is design.
When you go to break your problem into managable chunks, do you think "what parts make this up?" (OO), "what steps do I need to take?" (procedural), or "what operations make this up?" (functional).