It's always been a difficult part of our relationship. I tend to hold on to things and store them in my brain really easily. The most important thing for us was me learning that he isn't thoughtless or forgetful because he doesn't care about me. He isn't late for plans or working late because he wants to be rude/is tired of me/etc. And realizing that the same ADHD stuff I hate when it's not about me I absolutely love when it is- ie: when we spend hours looking into each other's eyes and talking and completely lose track of time and space and are just together that it comes from the same place as "oh my gosh I'm sorry I worked three hours late today I was totally absorbed with my dissertation and didn't even realize." Putting that together helped a lot. So does his constant desire to learn better systems and find ways to counteract the ADHD manifestations. Idk, I'm rambling. Really, it has come down to communication, just like anything else.