I've got to shake my head at these segments where the interviewer asks a philosophical question without seeming to have the conceptual maturity and framing to reliably go beyond delineating semantics. Luckily, Sanderson goes above and beyond.

10:31 – Is math discovered or invented?

The way it was posed sounds like it was asking for a dogmatic judgment on the nature of doing math, but I like Sanderson's take on how it looks to him, that certain mathematical problems seem discovered, and the mathematical tools developed to solve them and the frameworks they become seem invented.

14:30 – Difference between physics and math

Rather than tackling the philosophical question directly, Sanderson talks about the motivations mathematicians and physicists have when they do math / do physics, and that different people will give different answers.

17:24 – Why is reality compressible into simple equations?

Again, Sanderson provides a saner view: this feeling comes from that once you analyze out all your irrelevant details that you don't care about, or that you give up about (chaotic systems), what's left is what you can focus on by describing in simple equations.