I don't mean to sound callous, but for the most part, keeping people alive as an ER nurse isn't advancing humanity as a whole. Yes, your grandmother was a great person for doing it. But in the grand scheme of things, unless she saved the life of someone "important", she had no lasting mark on humanity, and you say yourself that she wasn't that important "(county hospital in rural area)", aka somewhere where she did a lot of good for people, but not a lot of good for humanity. Not to say that her job isn't important to people, but its not important to humanity as a whole except in a few off cases.