How do you respond to "I was always bad at math"? Here in the U.S., it is my experience that over 75% of adults I meet socially will volunteer that phrase or a variation upon learning that I am a mathematician.  I find this frustrating, since almost nobody would  brag about being bad at history or English or really any other subject.   Normally I change the subject, or perhaps say they must have had a bad classroom experience, but that feels unsatisfying and turns the conversation in an ugly direction.

Surely some of the bright minds here on Math.SE have found a good response. Note that I'm not looking to  alienate a new acquaintance, so let's keep it positive.
To put a slightly different spin on this (before @Zev votes to close :) ). When folks ask me what I teach, I ask them to name their least favorite subject. Occasionally I do get English or history or science. But 90% of the time I get math ... to which I reply "bingo." :) I then engage them in a discussion about how math (generically) and history (for me and many others) are ruined for the masses by secondary teachers who just don't get it and who teach relying almost totally on rote memorization/manipulation. They concur 99% of the time on this. At some point, I reassure them that there are some really good teachers out there (and I claim to be one) :P
Finding some practical application for math can get people quite a lot more interested; helping them to feel like they have a mastery of the numbers; and thus of the world around them.

That most likely sounded like a paragraph of BS though, so what I'm really trying to advertise is the LOGO Programming Language; the story of Seymour Papert's Lisp-like language for small children is filled with numerous instances of kids who were "never good at math" finding that they had really just been keeping away from it due to adverse learning experiences. Here's the book that I did my final term paper on. Here you have kids below 3rd grade, learning systems of geometry, degrees, and even programming idioms like subroutines, simply through the ability to experiment with them.

Applying those kind of ideas universally in a school system would be a huge undertaking, but it could apply very well in a private learning environment. Also: LOGO is old as disco, but the basic principles mentioned in the book are available in the 'turtle' library of Python.