This is because I forgot to bring the deck I built. I remembered all the other cards, and forgot everything I wanted to get it to work. Sometimes, necessity is the mother of invention.
So, I took the white and green and faked it for the rest of the night. It was a pretty aggressive deck, which means that if I didn't have my opponent on the ropes by turn four, I wasn't going to win. The cards I had just wouldn't allow me to grind it out.
Surprisingly, it worked pretty well. I won most of my matchups-granted, I was often helped by opponents having to mulligan in order to get workable mana, and then that mana not quite working out. However, a win is a win and, when the deck did fire on all cylinders I was attacking for six on turn 4, eight on turn 5.
Hey, it worked for a night.