Good Dick Day, or GDD is the uncontrollable size of your dick when you wake up, or when you finish working out, swimming etc. On a good day you have a nice shaft, with an enlarged head, on a bad day you have a shriveled up sleeve of excess skin surrounding a little moles head.
Mmmm I'm not going streaking like this, I'm not having a Good Dick Day.
I think I'll change in the shower cubicle, today isn't a Good Dick Day.
Skinny dipping? Hell yeah, I can feel I'm having a good Dick Day!
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.