Two funny stories have floated around social media for years. (I suspect both were made up.) According to the first, a woman complains about daylight savings time because the extra hour of sunlight cooks her grass. According to the second, someone complains that “wildlife crossing” signs are badly placed, because the wildlife crossings in those locations create hazards for drivers. The error is the same in both cases: A person wrongly thinks a description of something changes the underlying reality of what’s going on. It occurred to me that people who advocate so-called “gun-free zones” commit a similar error, in that they imagine that decreeing an area “gun free” will somehow stop criminals from using guns in those areas.