According to Buck, what is the most puzzling about the behavior of adults?
Buck finds puzzling the gratuitous cruelty of the adult men who have captured and caged him as he wonders what they want of him: "He could not understand what it all meant."
Buck is baffled about why these strange adults keep him in a cage and mistreat him so cruelly by not feeding him and not giving him water. And, to add to his confusion and puzzlement, some men leave him unharmed, such as the salon-keeper who merely opens the door to check on him by the dim light of a candle.
Further, Buck's feeling of puzzlement and oppression overwhelms him with a nebulous sense of danger and of misfortune that could come at any time, because whenever he hears the shed door rattle and he hopes to see the Judge or his men, there appear only other strange adult men, adults who puzzlingly torment him for no apparent reason.
The Call of the Wild by Jack London is considered by literary critics to be this author's perfect work. For, its naturalistic theme certainly plays well in the setting of the prospecting Klondike of 1897 in which man and dog, both creatures of an indifferent universe, confront a brutal environment that tests their survival instincts and strength.
In Chapter One, Buck receives a quick education about men and his relationship to them. In his life on the Judge's farm, he considers himself "king," not just over all the other dogs, but protector and companion of all the humans. He implicitly trusts the humans there, and feels that they respect him. When he is kidnapped and sold by the Judge's gardener, he is confused by his treatment and his situation; when he is choked to unconscious, thrown into a cage, and denied food and water, he "could not understand what it all meant," or what these "strange men" wanted with him. He rages against his captivity, biting one off his handlers, showing the "unbridled anger of a kidnapped king." What he cannot understand, "because he did not read the newspapers," is that the Klondike gold rush had created a great need for dogs, and he had been stolen to be sold as a sled dog. Buck is unaware of his economic value, but ultimately his theft and forced relocation to the north brings out his true nobility of spirit.