In "Soldier's Home," why does Krebs avoid complications and consequences?

Krebs gets back from the war later than most other soldiers, so he does not receive the hero's welcome that those earlier returners had. In order to be heard, to get some attention and appreciation, Krebs lies about some of his exploits during the war. He tries to portray a heroic persona, so that he might more easily fit back into society.

Eventually, he develops a feeling of nausea about telling these lies. Subsequently, even though he wants a girlfriend, he does not want to put in the work to get to know a girl, let alone reveal things about himself. He doesn't want to have to deal with conflicts or the consequences of his own lies.

He did not want to tell any more lies. It wasn't worth it. He did not want any consequences. He did not want any consequences ever again. He wanted to live along without consequences. 

Using this rationale of avoidance, Krebs prefers to watch girls from a distance rather than interact with them in any personal or intimate way. It was easier for him to engage with French and German girls during the war because talking was not an issue.

Krebs may also have had traumatic experiences during the war, not counting those he lied about. These possibly have affected his ability to engage his feelings upon his return. Krebs lies when he returns as a means of fitting back into a normal social world. His only means of relating to others is by lying. When this lying leads to uncomfortable mental and physical reactions, he simply doesn't want to, or doesn't know how to engage with other people.