There's a topic that I'd like to study (Maths) but I have 4 1/4 University degrees already (undergrad, MSc, some more undergrad modules, another MSc, a PhD) so I wouldn't be doing this for immediate career gain. It would be because I like Maths. What's holding me back now is the need to earn as much money as my disability lets me earn (still far short of a living wage) but with OU, there's no time limit. So perhaps I'll do it at some point.
How about you? I think people all over the world can use OU and there might be options in your own country too.