Hi, and I’m glad you enjoy my tumblr!
That’s a very large question, so forgive me for taking so long to answer it (also I had to send in my computer to get fixed and this is way too complicated to type on a smartphone).
Hi! I believe you’ve come across this post of mine; Google is a scary beast.
I’ll do my best to answer your question, but I’d like to note that I’m not the author/illustrator of said comic, and what I respond is only my own interpretation the piece/quote in question.
According to the 10th edition of Merriam-Webster, the first definition of “nature” is “the inherent character or basic constitution of a person or thing: essence.” Using this, we can say that the “nature of reality” is basically the “essence of reality.” Thus, by having mastery over the nature/essence of reality, one understands the basics of reality - why things tend to happen the way they do.
On the other hand, the “behavior of reality” is what actually happens, not necessarily why. So I guess the difference between the two terms is “nature of reality” answers the question of “How?” and “behavior of reality” tells “What.” You don’t necessarily need to know the nature of reality to tell of it’s behavior. Example: You can know the sky is blue (behavior) without having to explain why (nature).
And so, here’s my interpretation of what the SMBC quote: even if you understand and can explain what is happening and how it’s doing so, you can’t always change what actually occurs.
Hopefully that helped! I found the comic so tragic and so beautiful, I hope you’re now able to read it with newfound understanding and appreciation :)