how i know what i know

What makes us human? our ability to have language or is it the fact that we walk up right? the answer to this question is much more complex then any one thing. As humans we use prior knowledge to dissect situations and make the best decision based on the things we have learned prior. I believe i know what I know because i have learned it, the world has molded me into the person i am today. The idea of prior knowledge doesnt seem to be real because i have always seen how different situations give people different ideas about people and places.