When you are super hungry and EVERYTHING looks good. When you order tons of stuff to eat, only to find out afterwards that you weren't as hungry as you thought you were. e.g. "your eyes are bigger than your stomach".
Man, I was starving. I went to the store and bought a cart load of food. I had a big eye.
At Thanksgiving I tried everything on the table. I had mashed potatoes with gravy, yams with marshmallows, raisin walnut stuffing, turkey, green bean casserole, ham with pineapple and marachino cherries, buttered biscuits and cranberry sauce. My plate was over flowing. After having a few bites of everything, I was stuffed. I hardly touched anything on my plate. I had a big eye.