A grumpy patient

As you may or may not be aware of, I work in a locked psych institute. I hate it. I want nothing more in my life than to just be able to write for a living.
That being said, I had an interesting patient last night. This person is supposedly ex military with a pain med issue. (I say supposedly because it's sometimes difficult to judge reality with people, this person could just be REALLY obsessed with Call of Duty. The pain med issue is that this person doesn't get enough to drool all over them self.)
This person woke up from a nightmare and cussed out the nurses and myself for not giving out pain meds like candy. The med nurse got really upset and yelled right back at this patient. The patient then said, "Fuck you! You don't understand my pain! You've never been in combat!"
Here's where I get annoyed. First of all, how do you know the nurse hasn't been in combat? You don't even know his name, let alone any information about him. Secondly, do I have to have been in combat to know how traumatic that is? Really? I can't imagine or sympathize with your pain based on my personal history, which you know nothing about, and empathize with you based on your words, actions and my understanding? That's not possible? I'd have to have been next to you, to understand?
My how this patient's attitude changed when the nurse explained that he'd been 18 during the Vietnam War.
Don't presume to judge others because you have no idea what they've lived through. I've watched people die. I've created life and watched as it was literally flushed away. I know pain. It may not be your exact pain, but I understand what it's like to have life shatter in your very hands.
That mentality drives me batty. Then I remember I work in a locked psych institute. Most of the people there barely have the ability to cope with day to day life, let alone are able to grasp the social understanding that life doesn't revolve around you and that you're not that unique.
Sorry, I'm venting today. I hope you're day is filled with positivity, love and the ability to show someone they're important, for even just a moment. <3