I've heard that the ancient Greeks were the first and only culture to come up with the idea of maths for the sake of maths. Did they not get this idea from anyone else? Has any other culture independently come to the idea of mathematics that may not be "useful", but may be interesting for its own sake?
In The Savage Mind Claude Levi-Strauss makes the point that all cultures, even those that people consider "primitive", have classification systems and tendencies toward organization and quantification for its own sake. The idea that only the "most civilized" people have abstract, "purely intellectual" ideas while others only employ knowledge for practical or material purposes is one of the legacies of colonial racism. Levi-Strauss writes how among different hunter-gatherers in the Amazon, there is a level of classificatory detail about the natural world that goes beyond any practical purpose. When a new plant is discovered, whether or not it is useful, it is named and incorporated into the schema of categorization.
While this is not about math per se, it is an example that all cultures have intellectual needs as well as material needs, and that there is possibly some universal tendency of the human mind toward classification for its own sake, as an intellectual pursuit.
Al-Khwarizmis's book of Al-Jabr wa Muqabala is one example I can think of off the top of my head. I'm sure there are some Indian and Chinese mathematicians as well.