Because The Human Comedy is a novel structured essentially as a series of vignettes, in my view there are certain brief episodes throughout it, seemingly incidental ones, that reveal the most significant points Saroyan is making about small-town life and relationships, and about human life overall.
An episode in chapter 25 stands out in my mind. In it the Armenian grocer, Mr. Ara, is repeatedly asked by his small son for treats, fruit, and candy, and each time Mr. Ara complies, indulging him though the boy isn't finishing the apple, the orange, the banana, and so on. A customer, from his speech also probably an Armenian, enters and asks for cookies for his sick nephew. Though Mr. Ara has no cookies, he gives the man a bagful of fruit and refuses any money for it. Saroyan uses the episode as a parable about general human dissatisfaction and unhappiness, but it also illustrates the unlimited kindness some adults are capable of giving children.
Another event that stands out occurs at the very start of the novel, when Ulysses waves to people on a passing train and all of them ignore him except an African American man, who then speaks to Ulysses and expresses happiness over the fact that he is on his way home. It is one moment of bonding between adult and child which is small in itself, but again provides an example of the theme of kindness at the heart of The Human Comedy.
In my opinion these two scenes are among the most realistic episodes in the novel. The child in each case is a less mature version of the adult, but has essentially the same feelings and hopes and dreams as grown-up people do. Saroyan depicts the parallel between young and old in an especially moving way.