you know someone is partying hard when they are: crazy outspoken and is able to express themselves and stand out in a crowd. And being able to act in an authentically outgoing way; in such a way that this person one who defines the word PARTY means your the one who's partying hard. Partying hard only happens when the one who's engage in this action has lost exactly what keeps him from doing stupid things. they simply don't give a F*#$.
That dude over there is partying hard.
Yea i can't believe it, he's like total party boy status he's got more swag than the last rapper that flow'd about Obama