It is upsetting when I see posts from people I genuinely like, and they use developmental disabilities as a slur. This kind of language has real world impacts. Every time I read a post where someone is using mentally disabled as a slur my mind instantly snaps back to those two hours I spent with my sobbing 12-year-old student who is being bullied with this type of language by a kid who learned it from his parents who use the expression to belittle people that they don't like in popular culture.