Edge.org is a wonderful online version of “The Reality Club” and had a yearly tradition of inviting diverse thinkers to respond to stimulating questions over the 20 years from 1998 until 2018. For the final question, they invited a wide variety of people to give their own answer to: “What is the last question?”
Steve Omohundro’s response was:
How did our sense of mathematical beauty arise?
Other’s responses are here:
Steve is interested in the question of mathematical beauty because it represents an inner sense of what abstract models, knowledge, and inference is valuable that seems rather disconnected from ordinary evolutionary pressures. If we can fully understand the nature of mathematical beauty, I think it will shed light on unique aspects of human cognition.