Why do recruits call themselves privates or specialist while in DEP?

I am in DEP for U.S. army and feel a bit annoyed that everyone at the recruiting stations calls each other private this or that when they havent even gone through basic training. I am going in as E4 but felt ridiculous when one of the other recruits called me specialist, i feel this is a rank i have to earn by graduating basic , am i wrong, i feel strange asking the recruiters for the correct way to address each other , they hear this being said and say nothing ,shouldnt we all address each other as recruit, whats the deal here and name or last name?