I don't have a good answer for your question why didn't/don't you...why can't you just...why is it....
I've been reading through these forums tonight and seeing a lot of consistent things. Many of them echo the same things that my wife (non ADD) and I (ADD) deal with on a regular basis. We've been married for 14 years and have worked through many issues including her frustration with me and my ADD. I realized tonight what one of the biggest causes of friction is when we get in an argument and I see the the same thing through other posts. It has to do with how we respond to my forgetting to do something that was asked of me.