Why Do Atheists Know More About Religion?

Pew found that Jews, Mormons, atheists, and agnostics are better informed about religion. Jamelle Bouie's thoughts:

To me, it’s no surprise that the highest scorers after controlling for everything were religious minorities: atheists, agnostics, Jews and Mormons. As a matter of simple survival, minorities tend to know more about the dominant group than vice versa.

E.D. Kain largely agrees. Kevin Drum remarks that most "us just don't know very much about anything." Larison's adds his two cents. And Douthat labels atheists converts:

The very act of declaring yourself an “atheist,” after all, suggests a particularly high level of interest in religious detail and debate higher than many self-described Methodists or cradle Catholics who have a vague belief in God and show up at church on holidays, and also higher than the many nonbelievers who are merely indifferent to religion. Another way of putting it is that self-described atheists are the religious converts of the irreligious world. Like someone who leaps from Lutheranism to Catholicism, or Christianity to Islam, they’ve made an intellectual decision about their faith or the lack thereof, that is. And so it isn’t surprising that they’d be more knowledgeable about the subject than the much larger populations of part-time churchgoers and “nothing in particular” nonpractitioners alike.