Another from The Best of Chuck Central

I KNOW YOU ARE, BUT WHAT AM I ?

Once, as a youngster, I was getting harrassed by a very annoying brat at our apartment swimming pool. When I'd had enough, I pulled this one on him.

Me: How old are you?

Brat: Eight.

Me: How'd you get so ugly in just 8 years?

(He pondered it for a few seconds, then offered this witty ebonic retort..)

Brat: How YOU gesso ugly eight-TOUSAND year-uhs.

Note: That comeback was not exactly Verbal Judo. The Brat made the obvious mistake of giving me MORE time to become ugly. Clearly, a person several thousand years old would have valid reasons for being ugly.
He completely failed to address my original barbs implication that HIS face had deformed at an ACCELERATED rate. Here, the comic logic in the Brats assertion collapses. Rendering it painless, and non-humorous. He erroneously assumed that a larger numerical value, somewhere in the insult, automatically made it a Zillion times more worser, when turned on the opposing doo-doo-head.
An effective comeback allows no "Erasies", and may implicate Yo Momma.