Was there ever a completely non-horror movie that ended up scaring you?

There are two movies that gave me nightmares that are not considered horror movies, but non-the-less had very horrific scenes. One being Schindler's List, the other being Saving Private Ryan. The scariest thing about these movies is that it actually happened to people. My admiration of our troops was renewed upon seeing the latter. And there is an emense feeling of sorrow when I think of what all those people endured at the hands of the Nazis.