How does Toad's self-centeredness lead to negative consequences for himself and others in The Wind in the Willows?
When Toad is first introduced in Chapter 2, he is enamored by carts and horses, and convinces his friends Mole and Rat to take a trip with him. On the road they are almost run down by a swiftly moving automobile. Although the cart is wrecked, Toad's attention is now taken by a new interest - automobiles - and he leaves his friends to deal with the mess caused by the accident.
In Chapter 6, we find that Toad has continued to behave irresponsibly with automobiles, and Rat and Mole decide they must intervene, locking him in his room when he will not be reasonable. Toad escapes, causes another accident, and lands in jail. He then escapes from jail, engages in a number of deceptions in his flight, steals a horse, and in Chapter 10 is involved in yet another collision. In Chapter 11, Toad, who while on the run has fallen into the river, must be rescued by Rat.
In the final Chapter, Toad sings a song extolling his own praises while alone in his room, signifying that his self-centered nature remains as strong as ever, yet we are left with the feeling that he might have mended his ways somewhat, as he is humble and subdued when the others arrive.