What is a good comeback for takes one to know one?

Answer 1

"It takes one to know one" is a not-so-subtle put-down which attempts to use superiority and shaming to silence a person.

I'm not great in the comeback arena, but one example might be: "I guess you have personal experience to say that."

However, many psychologists believe that grade school and high school taunts are best dealt with by ignoring the person.

Some psychologists think that it helps to acknowlege any part that might be true, which takes the sting out of put-downs. No one can hurt you when you are upfront about a common problem. For example, many people get nervous speaking in front of the class. Often, it helps simply to acknowledge, "Sure I'm nervous."

Answer 2

That makes 2 of us

I don't know anybody called U either.

Answer 3

"How would you know? You're the expert."