Math at a basic level is intuitive. My hand has five fingers, I have two apples, etc. That's basic stuff my cat would understand. Everyone discovers it quite early in their lives. But math evolves - it's an organic idea that grows, builds upon itself, reinvents itself as it comes into new fields. Applied mathematics has touched every aspect of humanity, ultimately expressing itself through feats of technology or engineering. So I would say, as the.. sum.. of its parts, greatest ideas ever.