Answer :
Sergei is a secretive man. He does not like people asking him questions. When he lived in the Soviet Union, any knock on the door was the KGB asking questions which could get his family locked up in jail. Sergei used the first two wishes to look after other people. His sister was stricken with an incurable form of cancer. Sergei asked the fish to reverse the cancer. The second wish was to help his wife's son. Both these wishes show that Sergei cared about other people more than himself