According to the Pew Forum, "atheists and agnostics, Jews and Mormons are among the highest-scoring groups on a new Pew Forum survey of religious knowledge, outperforming evangelical Protestants, mainline Protestants and Catholics on questions about the core teachings, history and leading figures of major world religions."
Take the quiz yourself. But be careful not to score too high, lest your friends and neighbors mistake you for a Mormon or, gasp, atheist.
I scored 15/15, better than 99% of those surveyed. I guess that's what 12 years of a Catholic education buys one. Or perhaps it's just my nature. One can't be skeptical about something without learning about it first.
After the jump, some theories to explain the poor results in general.