"You're awful tall to be a freshman." ... now it was my turn to be confused, since 1. most males are about as tall as they're gonna get by the time they're 17 or 18, and b) I'm a little south of six feet tall even in shoes. So I shot HIM a weird look and said "what? I'm not even six foot." So he stepped up to the level I was on (stadium seating lecture hall) on the other side of the table, and noted that in fact he was about a half inch taller than I am (although a good forty pounds lighter). He paused to collect his thoughts, obviously still confused, and then started pointing out SIGNS OF SEXUAL MATURITY. "But you've got an awfully thick... [feeble gesture indicating beard] ... and, um... [gesture indicating chest hair]..."
So I said "I'm what you call a non-traditional freshman," and after a few minutes more of explanation, Things Became Clear.
Undergrad Confusion always makes me grin. =)