Either there is a pizza in the box, or there is not. But there mere act of opening the box may affect the status of the pizza. More research is required.
More to the point, as they say down at Schroedinger’s Pizza and Pet Shop, down on Quantum Drive...
“No really... pay up... there was a pizza in the box when we sent it out. Stop that already. It’s getting old.”
Bartender: "Well, Mr. Drill, there's either beer in that there bottle or there isn't. Should I uncap it?"
I don't like the universe very much.