Why don't we know much about the Olmec?

The Olmec civilization, often considered the "mother culture" of Mesoamerica, remains somewhat enigmatic due to limited written records and archaeological evidence. Their society flourished from around 1400 to 400 BCE, but much of their history relies on interpretations of artifacts, such as colossal stone heads and other sculptures. Additionally, the Olmec did not leave behind extensive texts or codices, making it challenging for researchers to piece together their culture, beliefs, and social structure. Consequently, many aspects of Olmec life remain speculative and open to interpretation.