Growing up, the only Jewish person I knew was my high school English teacher from New York who thought he was the hip and cool teacher but was in fact considered slightly weird because grown-ups aren't supposed to act like that and besides, it makes teenage rebellion not so fun.
But here in the Cleveland area, the Jewish population is (I've been told) the third largest in the United States, and occasionally I have to include kosher food requirements when planning food events. Previously, the only religious food constraints I knew of were Catholic (meat vs. non-meat on Lenten Fridays) and Mormon (caffeinated vs. non-caffeinated).
Kosher seems way more complicated. I thought it was just about pork, but in fact there's a whole list of foods and conditions. At one event the kosher food-checker rejected the bottled fruit juice I bought, which totally confused me, because what could possibly be objectionable about juice?
Fortunately, the Brick Testament provides a LEGO-land view of what not to eat.