It's wrong to think you're a failure.
Lyle made a bad grade on his test, and he is walking home from school.
Lyle wants to think about the future.
Lyle realizes that he can get better grades if he studies more.
Lyle thinks that the bad grade on the test means that he is a total failure.
Lyle is able to make a better grade the next time that he takes a test.
Lyle starts to believe that he is horrible and turns into a criminal.