This language of ours is always changing. At one point, if you really liked someone's eyebrows, you'd say they were "neato"; now you'd say 'those eyebrows ate." How delightful is that? Sure, it's troublesome when benign words come to mean something else entirely or develop a connotation in which they may get a time-traveler punched in the face, but for the most part, language's constant evolution is one of humanity's more fascinating features.