Answer:
Bob Ross is worth remembering because he looked at the bright side of everything. As said by him, "There are no mistakes, just happy little accidents." He had his own TV show showing tutorials on how to paint landscapes. He always looked at the beauty of nature and everything around him. As for why he was forgotten by history, I don't know the answer.
Birth rates were high, and death rates were high
They used their army and warriors to rule their empire, and the people feared them, giving the Aztecs control over the people