You probably don't experience much anxiety if you say that. Strong adrenalin-induced responses, or panic attacks even, are pretty much impossible to ignore. Try being social when you're shaky, sweating, and have shifty focus (i.e.: fight-or-flight response, your brain is looking for threats in your environment). It's hard slash impossible to will these kinds of symptoms away. Usually, this kind of social anxiety is only amplified by jumping into a social situation.

Furthermore, being even slightly inebriated from alcohol has a very noticeable feel to it. If I went to a party that only had non-alcoholic beverages but pretended these had alcohol, I'm quite sure that I'd be able to tell.