In Chapter 12 of the novel Bud, Not Buddy, why does Bud think he is not a regular kid?

In Chapter 12, Bud gets a ride from Lefty Lewis to Grand Rapids and is dropped off at the Log Cabin. When Bud walks into the club, he thinks he's spotted his real father, Herman E. Calloway. Bud listens to Herman tell a story about his younger days when he used to be a boxer. When Herman notices Bud for the first time, he asks him what he is doing here. Bud tells him that he's come to meet his father, and Jimmy asks him who his daddy is. Bud points directly at Herman, and Herman stops smiling. Bud says that if he were a regular kid, he would be crying buckets after seeing Herman's reaction. Bud says that he is glad that his eyes do not cry anymore. Bud has had a rough life and has the unique ability to repress negative emotions, unlike typical children. Instead of crying like a "regular kid," Bud continues to point firmly at Herman and says that he knows Herman is his father.