True heroes do not worry about what others think, they do what they know is right for them, and that makes Sammy a true hero. He may disappoint his parents, but he will not disappoint himself - ever. He also realizes that he has grown up in the few minutes it takes for the story to take place. He thinks to himself, "my stomach kind of fell as I felt how hard the world was going to be to me hereafter" (Updike 19). He knows that nothing will ever be as easy as it was to quit his job for the right reasons. He understands he will have...

In maturing, he is also heroic, because he understands his actions cause reaction in others, such as his family. Thus, he is becoming more responsible, even though his actions might seem irresponsible. Sammy is a hero because he understands the consequences of his actions, and makes a decision to stand up for the girls anyway. He might not be the most likely hero of a story, but he is a hero just the same.
References

Updike, John. "A&P." 14-19.