This is how I get over that hump. Not only do I not work on anything related to my day job, I mostly build things in my free time that aren't really useful to anyone but myself. Sure my company may be able to claim ownership of my Sean Connery themed programming language but will they? What on earth do they plan to do with it?
They are happy that you can't leave, because you have nothing to legally show to other interviewers and no other prospective project in your drawer. That's not a good position to be in.
