My son asked why I always put the pizza cutter in the dishwasher but slice the pizza with a butter knife

My son asked why I always put the pizza cutter in the dishwasher but slice the pizza with a butter knife.

Punchline

I told him it's called efficiency: the pizza cutter's already clean for next time, and the butter knife was already dirty from lunch. Why ruin a perfect system?

He said that makes no sense.

I said, "Welcome to adulthood, buddy—sometimes you gotta saw through mozzarella with whatever's already in the sink."