Previous discussion, https://news.ycombinator.com/item?id=14664150
One thing from the previous thread is that Andy has the time and the brains to dive deeply into this stuff. Andy is smart, but what I think sets him apart, is that he relentlessly drives to the root and he revisits the topic over long time scales.
Here is a talk Andy gave back in 2017. https://www.youtube.com/watch?v=iskjbi0lNQY
Now that you know the secret, Go Forth!
Update, if you find this stuff fascinating, I really recommend that you watch and follow along all of David Beazley's wonderful tutorial session, "A Curious Course on Coroutines and Concurrency" that ends in section 7 with making an OS scheduler loop.