August's birthday is the tenth of October, and he asks Mom if he can have a big party. He wants to invite his entire homeroom class plus Summer—even Julian, so that nobody gets their feelings hurt. A few weeks later, Mom tells August who agreed to come. Jack is coming, along with Summer, Reid, the two Maxes, and maybe Charlotte. August wants to know what people's reasons are for not coming, especially Julian's. Julian's mom was the only person who didn't respond at all, and Mom jokes that the apple doesn't fall far from the tree. August doesn't get it, but he does have a great time at his birthday party.
When August decides to invite Julian, it again shows that he's taking Mr. Browne's October precept to heart. This also has the effect of making any bad or rude behavior from Julian look even worse, as August hasn't done anything to warrant Julian's rudeness. Mom's comment alludes to the novel's assertion that children grow up to be a lot like the people that raise and guide them towards adulthood, which allows the reader to infer that Julian's parents are just as rude as he is.