One of the most important advancements developed by the Mayans was written language. The Mayans developed a complex system of writing, which consisted of both an alphabet, as well as symbols, which represented whole words or thoughts.
These writings were recorded in books made out of bark and plaster, as well as carved into monuments, bones and stone. Many of these writings have survived to the present, and help give us an accurate look at the Mayan's history and culture.
If you see no reason for giving thanks, the fault lies in yourself.