#2. Physical Illness
You know what the worst thing about having terminal illness is? Oh sure, dying is terrible and all, but even worse is people offering unwanted and often stupid medical advice. This is actually how many people with terminal illness come to terms with the end, because they realize they will at least have rest from all the people offering advice.
It's a very effective way of having the last word.
When author Christopher Hitchens got cancer, he found himself drowning in advice from well-meaning fans. The loopier ones suggested he try granulated essence of peach pit, testosterone supplements, opening chakras by meditation, eating macrobiotic or vegan diets, and even freezing himself cryogenically. Others suggested specific doctors or clinics all over the world that were the only ones that could save him.
Hitchens didn't mention how many people tried to recommend Dr. House, but probably a depressing amount.
Even people with chronic, non-terminal illnesses get this. One lady earned herself a "what the hell is wrong with you?" from a nationally syndicated advice columnist.
It seems like it should be really obvious that pestering someone with plugs for alternative medicine or telling a story about how someone you knew died horribly of what they have is not something most sick people would welcome.
"Oh, my mom had that. It turned out to be a parasite and exploded out of her chest cavity."
But still, people keep going up to strangers and offering cures from herbs to ox-blood to New Age chants, because they see a person with a cane and think they know the exact cure for... having a cane. Like the author of that article suggests, probably a lot of the reason that well-meaning people do this is because they're scared at the thought that there are terrible diseases out there that can't be "fixed". They want to believe that life makes sense and you can live to a ripe old age as long as you use the right cheat code.
"Squats twice a day, everyone, and soon you'll be right as rain."
Other people just have trouble figuring out how to talk to someone with cancer or a chronic illness, especially since everyone's different, but it's really not that complicated, you ask them. They're human beings and can tell you. Maybe they've got a macabre personality and actually enjoy hearing stories about people dying horribly, who knows.
#1. Mental Illness
So say someone -- a close friend, a co-worker, a random stranger on a forum -- tells you that they've been having some hallucinations, black out sometimes, are feeling depressed, and find themselves lashing out at people.
a) Tell them they're just stressed out and they're making a big deal over nothing.
b) Pull out your DSM-IV and diagnose them with Borderline Personality Disorder or another disease.
c) Diagnose them, then prescribe medication.
If you picked any of those choices and didn't consider telling them to see a professional, you have Clinical Armchair Psychologist Syndrome (DSM-IV-TR, 2000) and recent studies recommend 2-5 self-administered slaps to the face until the symptoms wear off.
Slaps should be delivered just hard enough to knock off your sunglasses.
Don't feel too bad, it's a pretty common disorder, especially on the internet, which is really weird considering that's the place where you would have the least information on the people you're diagnosing. One possibility is that on the internet, people's description of their problems is in text form, which makes it easier for us to make a pattern-recognition link with that psychology article or textbook chapter we just read. Also, people cloaked in internet anonymity usually feel freer to go into more detail about mental symptoms they'd normally be ashamed to talk about in person, giving the armchair psychologists more ammo to work with.
"This is the only way I can get off now."
The opposite side of the coin from people who want to slap an official DSM label on every unusual behavior are people who belittle serious symptoms. You see this most often with depression, which way too many people seem to think means "feeling sad." They hear someone talk about how they've been diagnosed with clinical depression and come in with, "Yeah, I know what you mean, I've been depressed before, when my turtle died."
It was a solemn day.
They'll belittle any suggestion of you going to a therapist or taking medication, because they didn't need any of that to get over their turtle. You just need to start thinking about all the people in Africa that are worse off than you (they don't even have turtles to be sad about), and then you'll be grateful for what you have and ditch your pity party. Never mind that actual depression is a diagnosable condition that can be caused by physical chemical imbalances and deep-seated mental issues. No, you just need to man up and shake it off.
Anyway, there is one piece of unsolicited advice that I will give to you: next time you want to give someone some advice about something, maybe think twice about whether you're being a dick about it.
Check out past articles from Christina, in which she ran down The 6 (Wrong) Questions Men Love to Ask About Women and revealed 6 Secret Monopolies You Didn't Know Run the World.