How does the crystal merchant influence the boy’s actions?

By revealing his own failures, the crystal merchant teaches Santiago that dreams can be dangerous, prompting Santiago to stay and give up his dream.

The crystal merchant shows the boy the Soul of the World, revealing that the crystal shop was the boy's prize all along.

By sharing his story and his regrets, the crystal merchant teaches the boy that some people would rather fantasize about their dreams than live them.

The crystal merchant allowed his opportunity to pass him by, teaching Santiago that you only have one chance to realize your destiny.