The idea is not to have any 90-degree angles. In the beginning, there was the diagonal. The diagonal comes from the idea of the explosion which "re-forms" the space.
"A great book is a great teacher."
I'd rather make mistakes than do nothing.
One strategy: "We've had three big ideas at Amazon that we've stuck with for 18 years, and they're the reason we're successful: Put the customer first. Invent. And be patient."