Why is the “Take Your Kid to Work Day” so meaningful to Donald? What does Donal learn about his dad’s work in their day together?

Chapter 11, "Mailman," establishes that Zinkoff's mother is not the only person from whom he got his kind and loving nature. Mr. Zinkoff, a man with a modest job who is a hero to his son, treats the boy with understanding and respect. When the rules of the larger world make it impossible for Mr. Zinkoff to bring his child with him to work, he figures out a way to bring the job to the child. The warmth between father and son in this chapter is signified by the gradual switch from calling the boy "Zinkoff" to calling him "Donald."