Yeah, I wonder how 'passive' got entered into the equations. Developing a useful course, getting feedback and evolving it, promoting it, all sounds active, not passive. I'm not sure how a course bubbles to the top of search (whether on Udemy or organically in Google, or Medium for that matter), but I imagine it's an ongoing game if one wishes to stay there. I agree that 'teaching' such a course appears to be little more than talking a lot about a thing, not building a theory and a comprehension. No matter though, the income potential is there, whether it's passive or ignoble. So yeah, it got my attention and I'll give it some consideration.