How often do you question your assumptions

Talk about a marketing nightmare. This article refers to a hunting gathering tribe that lives in the forests of Brazil. They number about 310-350 in population. So far so good, nothing extraordinary here. Then it gets interesting, this is a tribe that does not have numbers in its language, they do not have a system of counting, they do not have a way to distinguish past from future, they always live in the present. Mothers do not pass on fairy tales to children and to me the most fascinating part is that they do not have a creation myth.

For all practical intents and purposes they seem to have curiosity, they just exist. They do not try to learn from their past, they do not seem to plan or build towards their future. Where do they fit in with our world view. Now the assumptions part, I assumed every human being was created with a burning desire to more the exist/survive, I am not sure anymore. Thoughts.... ?