My Dad Can Beat Up Your Dad

Why do kids always say this? And what will my kid say?

Kid: My Dad can beat up your dad.
NinjaSon: My Dad's dead.
Kid: Oh sorry...
NinjaSon: But he just killed your Dad.
Kid: What?
NinjaSon: Live with the guilt...let it be your pillow...
Kid: What are you talking about?
NinjaSon: ...a pillow full of pointy things.