Bagel Bites

I had the Bagel Bites theme song stuck in my head whilst in the bathroom today. The refrain is something like:

"Pizza in the morning, pizza in the evening, pizza at suppertime...when pizza's on a bagel, you can have pizza anytime!"

Now, I really like Bagel Bites and the Bagel Bites theme song, but why does the fact that the pizza is on a teeny bagel have anything to do with when you can have pizza?