The ultimate irony in "The Goldfish" lies in Ivan's failure to fully grasp the consequences of his wishes despite having witnessed their negative effects multiple times. He repeatedly makes wishes that are seemingly innocent or straightforward, but each wish results in unexpected and often disastrous outcomes. This highlights the theme of human folly and the unintended consequences of our desires.
For instance, Ivan wishes to be the most attractive man in the world, only to find that his good looks lead to him being objectified and treated as a mere physical specimen. He wishes to be the richest man in the world, but the economic chaos his wealth causes leads to a dystopian society. Even when he wishes for something as simple as a sandwich, he ends up creating a war between Earth and an alien race.
The irony comes from the fact that Ivan's wishes are intended to improve his life, but they consistently lead to absurd and undesirable outcomes. The more he wishes, the worse his situation becomes, and the story ultimately serves as a commentary on the human tendency to pursue desires without considering the potential negative repercussions.
In summary, the ultimate irony in "The Goldfish" is the repeated failure of Ivan's wishes to bring him happiness or success, despite his initial expectations, showcasing the humorous and ironic twists that occur due to his misguided desires.