You've missed a step here. No one thought to do math until people started to seriously worry about proportions, distance, quantity, time, etc of the natural wor

You've missed a step here. No one thought to do math until people started to seriously worry about proportions, distance, quantity, time, etc of the natural world. Once you've set up those rules (and necessarily rigged them in favor of explaining the natural world) you can stay in the platonic realm, change the rules so they apparently stop reflecting reality, and rely on your sense of aesthetic, but then I think the onus is back on you to explain where this sense comes from.