The boy in the striped pyjamas

I have just finished reading 'The boy in the striped pyjamas' by John Boyne. To be honest it totally disappointed me because I had really high expectations. To begin with I despise children but that's not something that can't be overcome since I've many books with children as maincharacters. But this maincharacter , Bruno, was particularly annoying. He's naive, spoiled and stubborn; thinking he's the most unfairly treated boy in the world. He then meets a boy wearing a striped pyjama, named Schmuel. Schmuel is a Jewish boy stuck in Auschwitz. Although it's quite obvious that Schmuel is suffering, Bruno is competing with him to be the boy that gets treated the poorest. When it doesn't go exaclty like Bruno wants it to go, he tends to get really annoying. They both arrived by train; Bruno in a passenger train, Schmuel in the train that deported him to Auschwitz. He told Bruno they were stuck in a room with 11 people for months, he got beated up by older boys and then they were forced to travel by that horrible train. He said there wasn't enough room for all the people; taking away all the oxygen. Bruno says: "you had to go out then." But Schmuel said that there were no doors in the train. Bruno persists that there were and when Schmuel keeps contradicting him, Bruno says really childish in a big sigh, so that Schmuel couldn't hear what he was saying: "yes there are." Just to get it his way.
Another part that really really annoyed me was when Bruno decides to bring Schmuel food as he kept saying how emaciated Schmuel looked. However, walking from his house to the camp he keeps eating the food that was meant for Schmuel. Can you believe that. No nine-year-old child is that stupid. You make a promiss to someone, say that you'll bring food and you keep eating it every time and time again, because you are too weak to lay your hands of the food... Also eating all the delicious food right infront of Schmuel. The poor guy...