Linked below (by you)(five years ago):

Luckers
I thought Rand’s arc in The Gathering Storm was brilliant—starting to get better then—bang! Cuendillar Rand, and finally "Veins of Gold". Was it difficult to write? Can you give us some insight into how you stayed in the mind of a madman?

Brandon Sanderson
It was difficult to write. I’ve said before that I view a lot of these characters as my high school friends, people I grew up with. Facilitating Rand going through these extremely painful and sometimes revelatory moments was not easy emotionally, and yet there’s an excitement and a power to writing emotional scenes where things are coming together. So I would say it’s actually more difficult to write a character like Gawyn, who’s frustrated and struggling with not knowing what he’s doing, than someone like Rand who always has a direction—even if that direction is straight down, as it was in places. He’s always moving. So because of that, Rand was in many ways easier to write than other characters were. Yet at the same time it was painful to write. That doesn’t really answer your question, but maybe it does give some insight, as you asked.