The author said he really "intended" to take the class, but did he? Or did he just like the idea of it?
Learning is hard work. Learning difficult subjects is harder still, and it's very demanding of your time. There's really no way around that fact.
Let's be honest here, a lot of subjects sound interesting, but are you really willing to put in the time and effort to learn about them? It's never going to be painless.
I'm pretty much constantly in a Coursera course, but I drop half of them. I'm over feeling bad about it. Turns out I wasn't as interested in the topic as I thought. For other courses I am, and I do the work.