ADD is not being able to control what you focus on. There are things that you simply can't focus on without becoming exhausted, and things that you can't not focus on, where even when you force yourself to stop doing them you keep thinking about them long after, distracting you.
As far as I know there is no reliable way to control which things we hyperfocus on, they seem to be a fundamental part of our character. If you hyperfocus on a useful, productive and practical task or skill, ADD can be a blessing (although you still have to survive in a system designed for people who can more-or-less choose what they focus on at will). Otherwise, well...
I'm diagnosed with ADD. And even though sometimes it seems like everyone else is too, no one really seems to understand it, sadly not even those who live with it. This post documents how I've come to understand my "disability". Hopefully it can be useful to my fellow ADD-havers, to parents and to educators and employers.
I love video games, and I'd really love to get into them. I'm envious of my friends who can get emotionally invested in a 300 hour RPG. But I can't focus on them for more than half an hour or so at a time, so I only play games that are designed to be played in short sittings. Arcadey games. I don't consider this a bad thing, because spending time on video games isn't exactly productive, but I wish I limited my play by my own volition, not because of some mental limitation.
I also can't focus on studying. Unlike video games, I have strong incentive to force myself to study, so I do. But it's exhausting to focus for long periods, and after a couple weeks this leads to depression for me and I can't even force myself to do things that require no focus, like a netflix binge, let alone study. This leads to me often starting the semester off well, and then quickly degrading in performance. And since classes have to start off slow, the time interval during which I perform well is also the interval with the least impact on the final grade.
I hope this doesn't sound like me just venting about how horrible my life with ADD is. I'm trying to provide a case study of how ADD actually affects someone. I'm actually quite well off because I hyperfocus on computers and programming, which society values relatively highly, and is something I can build a career around even if I never finish school. While I can't focus for long sittings on video games, or my studies, or hobbies I want to pursue, I can spend a whole night programming or configuring a fresh linux installation while hardly noticing the passage of time.
I have a friend who hyperfocuses on music (performance and composition). He's really good at it and while he won't get a cozy 9-5 office job, I'm quite certain he'll be able to turn his passion into a career. I have another friend who hyperfocuses on video games, and I can only hope he finds a way.
Outside of programming, the only time I experience that long-term focus flow state in on amphetamines which force me to focus on EVERYTHING. I see kids who refuse to take their drugs get a lot of shit from people who think they know better. They get mocked for complaining that it changes their personality, and people tell them that it's all for the best. It disgusts me. Stimulants don't make someone with ADD into a "normal" person. You don't get to choose what you focus on. Just like with hyperfocussing, you can't NOT focus on whatever is put in front of you. If the first thing you hone in on is the paper you need to write, great. But then you stop to go to the bathroom, and when you come back, before returning to the paper you hone in on the pull-cord of your blinds and bat it around like a kitten.
And you know how I said I don't notice the passage of time while hyperfocusing? Same thing applies when mindlessly fidgetting with the blinds, or spinning coins on the desk, or repeatedly throwing my phone into the air and catching it. This can go on for uncomfortably long before I realize I've spent the last hour doing absolutely nothing.
I waste my time on such things anyway, but without the drugs I can catch myself much earlier — because I lose focus on time wasting just as easily as everything else.
Even more dangerous is focusing on something productive that isn't the task at hand. I've sat down to try to start and finish a final paper with a three days to go, managed to get distracted by a (computer-related) project that had been stewing in my brain for days and had just come to a head. I slipped and let myself work on it for an hour after making decent progress on the paper, and then spent the rest of the day working on it. And the whole night. Until the stimulants finally wore off and felt so sick (from forgetting to eat all day) that I had to stop. The next day I had an anxiety attack because I had squandered a whole day (and messed up my chemistry probably), and finally the next day I managed to squeeze out the paper, no drugs involved. It got a C-.
ADD isn't about not caring enough to perform up to expectations. It's not about being lazy. It's not about being easily distracted, or a lack of willpower, or only being able to focus on the things you feel like focusing on. It's about a lack of control over your capacity to focus.
Note: There was an interesting discussion on HN.