Coins are literally the currency between John and his father—a symbol of their relationship. With no interest in or ability to discuss anything else, the only way John’s father can connect with his son is through coins. Their discussion of coins directly relates to the state of their relationship. When John was young, searching and acquiring coins was something they did together. However, when John became a difficult teenager, he stopped collecting coins and even told his father that he didn’t want to discuss them anymore. After that, John and his father have a strained relationship, unable to connect over anything else. Once John realizes that this is all his father can discuss due to his Asperger’s, he opens up the conversation again, and for the first time in a long time, John feels close to his father again.

Coins are also how Savannah connects with Mr. Tyree, and she discusses them with him when she first meets him. She understands him before John does and knows this is how to connect with him. Her insights lead John to reevaluate his father and their relationship.

Even though John sells the collection, he keeps the buffalo head nickel that he and his father found together, the finding of which is commemorated in the only photo of father and son, which John also keeps.