The difficulties that nature presents was what made man insensitive to the beauty of it.
Explanation:
The poem shows how nature builds organisms within the challenges and difficulties they have to face in order to grow. These challenges are not easy, but it allows organisms to live and develop in a strong and edematous manner. However, these difficulties and challenges that nature poses, make people insensitive to their beauty and worry only about what they will face.
The main idea would be how problems of the past influenced the making of paper money. Paragraph 14, “But eventually people got tired of carrying around all that metal.”