I think when you truly start suffering consequences that are a direct result of your behavior you may wake up and start controlling yourself.

Until then, you should know that using foul language, even with coworkers, is a way you disrespect people. People are not using that kind of language to communicate with you, why would you do that to them?

RE: The Subway employee saying she couldn't hear you and you yelling at her - one day Ruby you are going to yell at the wrong person. The Subway person had to be professional, but if you yelled that way at someone who wasn't at work, you'd probably be getting yelled at back or worse.