Several ideas come to mind from the past few months:
If you're not wasted, your day is.
Surprise! I'm drunk!
You only have one liver, so live 'er up!
Several good/worse taste ideas for phrases at tshirthell.com
"There's those thinkin' more or less, less is more, but if less is more, how you keepin' score?
It means for every point you make, your level drops. Kinda like you're startin' from the top..." "Society" - Eddie Vedder