At the beginning of the story, the protagonist of the story is at war. He is a soldier currently trying to snipe an enemy. Although, he is in danger, he decides to light up a cigarette indicating that he is reckless and impulsive.
His actions have consequences though. As he was attacking an enemy car, the enemy sniper shoots at him and hurts him. He knew where the protagonist was located because of the cigarette smoke earlier.
As this happened, he stopped being reckless and changed into a whole different mindset. Now, he was cautious and careful of himself. The sniper went to tend to his wound and hid out somewhere else. I, personally, think this change is a good thing, as do many.