I qorked at subway for 2 years, ive been spoken too like im slow or talked to like im dumb. Yhe trick is to just smile and get through your day. You dont have to jump at the opportunity to feel like someone is offending you. So what someone changes thisr tone, its the same when you interact with someone with special needs, you'll change your tone, watch what you say, its just being cautious for something your not familiar with or used to seeing. Just smile ppl are just curious and most are very understanding, aside from those who arent but dont react with anger ever, otherwise you'll just be avoided and make it known that your "that guy who gets mad when ppl talk to him" remember, you get reactions based on your own actions,not others.