Well, he did tell me that he didn't drink until he turned 21 that's for sure. I met him on my 21st birthday, and I mentioned that I hadn't had a single sip of alcohol all day, he seemed to relate to the desire to not drink.
I think he just uses the word "party" to mean more of a jubilance towards life. That every day is a party if you want, that you need to enjoy life and not waste it wallowing in self pity. You know, a you only live once sort of mentality.