The memories will cause Sergei to use the last request to save Yoni's life.
Although you haven't shown it, we can see from questions similar to yours that your question refers to Sergei's memories of the requests he had made to the magical goldfish in "What of this goldfish would you wish?"
When we read "What of this goldfish would you wish?" we can find the following information:
Sergei has a magical goldfish, which is capable of granting three wishes.
Sergei has already used two of these wishes, to help other people and not for his benefit.
He wants to keep the last wish for himself.
However, he ends up causing a very serious accident to a boy named Yoni.
This accident puts Yoni's life at serious risk.
Sergei doesn't want to use the last wish to save Yoni, but the memory of how he used the previous wishes makes him feel responsible for Yoni.
These memoirs show that it is unfair not to help Yoni, as he helped people with problems who were not provoked by him.
These memories cause him to use his last wish to save Yoni's life and although he feels sad that he didn't enjoy any of the wishes, he knows this was the right thing to do.
