I knew he was wrong. He was staying in the army because he wanted to stay in the army, not because of duty or anything else
[k]nowing that about Sam gave me a funny feeling. I didn't feel like his little brother so much anymore, I felt more like his equal.
Tim speaks these words after Sam comes home and refuses his mother's plea for him to stay home. For as long as he can remember, Tim has fallen short of Sam's strength, courage, intelligence and experience. Tim's idolatry of Sam remains constant through much of the story. Even when Tim becomes the man of the tavern, performing adult tasks and making important decisions, he still looks forward to the moment when he can show off his new knowledge to Sam. This quotation marks the first time when Tim deeply disagrees with Sam. Tim has discovered a fundamental truth about Sam: once Sam has become part of a group that might achieve glory, no amount of arguing or persuasion could rip him from the group. Usually Tim argues just to act as a foil for Sam, but this time he sincerely believes that his brother's decision is wrong. Having learned this, Tim is finally able to understand that his own rationale is as sound, if not sounder, than that of his older brother. This realization shapes his developing adult personality.