When I was in my late twenties, I ran across a checklist for depression. I was shocked to discover that I had nearly every symptom listed on it, and had for more than twenty years. I got treatment for it and discovered that life was nowhere near as difficult, painful, and pointless as it had seemed until then.

A couple weeks ago, I made a similarly shocking discovery: the differences between me and most other people, which I had always considered personal failings, are actually symptoms of a well-known medical condition. (Well-known now, anyway… when I was growing up, it was practically unheard-of.)

The symptoms of it almost read like my own biography:

• Problems with verbal communication. I’ve never been very good at talking. I can write very well, but trying to come up with just the right words in real-time conversation is very challenging. I often know that there’s a word that describes the concept I’m trying to get across, but I can’t think of what it is, leading to awkward pauses. Given time I’ll be able to come up with it, but it’s extremely frustrating, both to me and to listeners.

• Extreme sensitivity to certain senses. I’ve always been way more sensitive to light, sound, and touch than most people seem to be. I prefer the volume on TVs and radios turned much lower than most people like, and I regularly irritate my wife by singing along to whatever she’s listening to on her headphones, which most people wouldn’t be able to pick out. I can hear when the taps are getting hot, by listening to the change in pitch of the water pipes as they expand from the heat; it shocked me to learn that most people can’t. I have to squint even on cloudy days. I can’t stand anything more than very mildly spicy, and I have to warm cold things like ice cream before I can let them touch my teeth (things like Sensodyne toothpaste have no effect on it). I prefer my beverages at room temperature or just a little warmer or colder; ice cubes in drinks are right out.

• Seems to have a heightened or low response to pain. As a child, I used to think I must be a wimp because I reacted to pain (both physical and mental) so much more than other people, so I learned not to react to it. But now I find that it wasn’t just that they didn’t react to it as much, they actually didn’t feel it as much. It would have been very comforting to know that at the time.

• Unusual distress when routines are changed. I absolutely hate it when I’m forced to alter my routine. Travel is unpleasant. Moving to a different house is just short of traumatic, even if it’s in the same city — a lovely trait for a military brat whose family moved every two years. When I work on a program, I continue working on it for years if there’s enough to keep me busy. Much of my programming is centered on ensuring that the code will do the same thing regardless of the input thrown at it… I’ve never understood how most programmers can work on something only long enough to make it work most of the time, and only in the specific case they need it for.

• Unusual attachment to objects. My need for sameness extends to the objects around me too. When I buy things, I always look for the ones that will last the longest. I’ve had my current car for ten years, and it was used when I bought it. I get very distressed when something breaks, even when it’s only minor damage.

• Shows a lack of empathy. Most children seem to intuitively understand why other people are doing things, and what they’re feeling. I had to learn to read body language, facial expressions, emotions, and intentions. I’ve gotten pretty good at it, better than some “normal” people, but it never came naturally to me. And those skills didn’t directly give me the ability to discern what people wanted, or why… that took many more years to figure out, and I still don’t always manage it very well.

• May not respond to eye contact or smiles, or may avoid eye contact. As a child, I watched people’s faces, trying to figure out what they were thinking. Somewhere before school age I figured out that if someone smiled at me, I was supposed to smile back, so I started doing so. It was several more years before I figured out why people got nervous or annoyed when they looked at me, and stopped staring at their faces all the time.

• “Acts up” with intense tantrums. Though not too often, because my mother was a firm believer in corporal punishment, and as I said above, I feel pain more than most people.

• Does not make friends. Prefers to spend time alone, rather than with others. I wanted to have friends, and spend time with other children, but how can a kid make friends when he doesn’t understand what other children want? And the older a child gets, the less tolerant other children are of differences. Why spend time around people who are cruel to you, especially when you’re more sensitive than most? As an adult, I always thought I was just shy and introverted… apparently not. (Though there’s now a theory that introversion is actually a mild form of this, that’s what led me to discover it.)

• Has very narrow interests, but obsessive interest in specific items or information. If there’s any single sentence that describes me, that’s it. I just have no interest in most things. The obvious down-side of this is that it’s very hard to force myself to do anything that I’m not interested in. Mildly unpleasant but routine things, like exercising or cleaning the cat boxes, are very difficult for me, much harder than they seem to be for most people.

• Unwanted social isolation can lead to anxiety and depression. I’ve stated my history in that area. That generally manifests at about school age, because that’s when you start dealing with other children, and that’s certainly when I started feeling that way.

• May find certain background sounds, which other people ignore or block out, unbearably loud or distracting. I can’t have anything with words playing while I try to concentrate, or have any conversations going on within earshot.

On a self-assessment test for this condition, most people who don’t have it score about twelve. Those who do average thirty-two. I scored thirty-five. (EDIT: See the comments for a link to the test, if you’re interested.)

Just a few days ago, my mother was talking to me about one of my nephews, and how he seemed so similar to me. I love the kid dearly, but I had to say that he really wasn’t much like me, and enumerated some of the above items. When I mentioned the name of the condition, she said that she’d heard of it a few weeks ago on TV, and the description immediately reminded her of me. Furthermore, my father was apparently very like that as well (I never knew him, he died when I was three). It is, in the words of one web page I found, “extremely heritable, but not inherited” — as I understand it, that means that it’s genetic, but the genes responsible aren’t usually expressed in sequential generations.

There are other symptoms that I’ve overcome: as mentioned above, I’ve learned to read body language and understand tone of voice, gestures, and facial expressions, and I learned early the need for tact. There are also a few that I don’t think I ever had: I do care about others, and show it; I don’t avoid eye contact under any circumstances (I tend to make eye contact too much, in fact); and I recognize metaphors and similes and don’t take them literally, most of the time. But those are the exceptions.

I’ve carefully avoided naming the condition, as I’m sure you’ve noticed. When people hear the name, they think of the more extreme forms of it, which are very obvious and debilitating. People who knew me well during my childhood (like my mother) might immediately see it, but few who met me as an adult would suspect that I have it — I told my mother-in-law, a retired teacher who has worked with children with this condition, and she was shocked; she said that she never would have thought it.

The condition is High-Functioning Autism.

I have more to say on the subject, but I’ll save it for a second article.