From "The Red Badge of Courage," what evidence in the passage reveals that this will be the first time that Henry is leaving home?

His mother tells him to be careful and to not fall in with a bad group of soldiers. Then she says: "I don't know what else to tell yeh, Henry, excepting that yeh must never do no shirking, child, on my account. If so be a time comes when yeh have to be kilt or do a mean thing, why, Henry, don't think of anything cept what's right." You get an explicit feeling that this is the first time Henry is leaving home.