Intern has one sensible drink at the holiday party. Real employee gets blackout drunk.
Intern office attire: DRESS TO IMPRESS.
Real job attire: Whatever the hell you can find that doesn't smell like mud.
When your boss IMs and asks you to do something as an intern: OMG, yes, anything you want! I'll do it right now!
When your boss IMs and asks you to do something at a real job: LOL, ZERO FUCKS.