In "To Kill A Mockingbird" is it a surprise to find out what Boo Radley is really like?Has the story before this point prepared the reader for this discovery?
If you pay close attention to the story along the way, it shouldn't surprise you that Boo Radley is a nice person, who is willing to help the children. Instead of being upset at Scout for launching herself into his yard when she was riding in the tire, he was laughing at the spectacle of it all; he was amused by her. The fact that he offered them tokens of friendship in the tree also indicates that he is friendly. Then, after Miss Maudie's fire, Scout finds that she is covered in a blanket, one that Atticus hints was put there by Boo. All of these clues indicate that Boo was a passive participant in much of their childhood, very friendly, and cared about their safekeeping.
It IS perhaps surprising that Boo took such ACTIVE action at the end; that he came out of hiding to confront such a dangerous and violent situation is quite a change-up. However, he reacted emotionally to Jem's scream, and did what needed to be done. And we come to discover that he is a just a man-a bit pale, but a man nonetheless-who acted as any other decent man would have to rescue Jem and Scout from the clutches of Bob Ewell. We also discover how fond he is of the children; his actions in saving them, then his desire to see Jem at the end, indicate, as all other events did, that he was fond of the children. A close reading of the novel supports that notion.