MFA vs. PhD

I finished my MFA in Illustration (with honors) at the University of Edinburgh in May. It was a wonderful two-year-long chapter of non-stop visual creativity. I drew, painted, screen-printed, relief printed, and generally made a big mess! It was fabulous and I can't remember a time in my life when I was ever as densely creative. I could be an MFA student for the rest of my life and be quite happy.
     But, now I'm doing a PhD at the University of Glasgow (photo) and I am in a completely new life chapter. This chapter is all about reading and writing. I still illustrate (and have a book coming out this fall), but my primary exercise is research. And y'know what? I love this too! I'm learning new ways of thinking and expanding my brain. If my brain can indeed only hold a finite amount of information (as Andy Rooney used to propose), then it will soon be coming out my ears! All said, I just love being a student—researching, creating, exploring. It's something I think we could all do more of, even in an unofficial capacity.
     I've come to think of my creative time as theme-related, rather than just creating one-off, random trials. I explore my art in themes—like in my Marginal Creatures project that ended up as a book. Or in a drawing pad, in which I use the same madia—i.e. biro pen throughout one, a micro pen throughout another, soft lead in another; or exploring the same subject matter—i.e. birds, mice, fantasy designs. On the writing side, it's collecting ideas for articles, stories, academic inquiry, or a novel. On the reading side, it's all about my PhD topic, of course.
     Thinking thematically has allowed me to thoroughly explore ideas, end up with bodies of work, and achieve a sense of completion once I have that body of work (that I can either enjoy as completed or try to get published). I like this new way of creating and learning. What do you think, would that work for you?