When considering why Henry was irritated with his mother in The Red Badge of Courage, the most effective reading strategy to realize this is reading between the lines to infere. At any moment it is said that he feels irritated with her, but there are two instances in chapter 1 that shows that. The first one is when he prepared himself emotionally for a warm welcome from his mother and she seemed cold and far away from him, while the other is when he was about to leave to the army and his mother gave him a moral speech. 'It had not been quite what he expected.' Whe can infere that he expected a hug, a kiss and an I love you, instead of rules of good behavior.