Okay, this one is a little to out ther-

Wait

16 is 4 squared, and squares have four sides, and diamonds are just squares turned sideways, (and before you say anything, you're thinking of a rhombus), and special rectangles, and pizza is in the shape of a rectangle!

Then that could only mean!

that i'm full of shit, and the first person who see's this should just crash a meteor right on my fat face.