Why was igor unhappy about his spelling test even though he got evrything right?

Igor was unhappy about his spelling test because, despite getting everything right, he realized he had made a careless mistake by misspelling the Word "everything" as "evrything." This error made him feel frustrated, as he believed it overshadowed his success. He may have also felt that his effort was undermined by that single mistake, leading to disappointment in his performance.