This story is about building self-confidence. Trusting your abilites for risk-taking which may lead you to personal achievement.
Through small wins and accomplishments the boy and the Saguaro cactus build their self-confidence. The Saguaro cactus accepts the boys challenges because they challenge him. When you accept a challenge because it challenges you, you are building your self confidence. Have you ever spoken to yourself and said?
"I have done that so I can do this."
This means you have some self-confidence in your abilities.
Read this story to see all the impressive ways the boy and Saguaro cactus go about completing things that challenge them in their own interesting way!