I was worried that the heart flutters I was experiencing were due to my ADD meds, so I cut them in half for two days and forgot them entirely on the third. I then went back on them, but it was long enough to realize that there is a cumulative memory effect, which is SO STRANGE. On the fourth day, after being back on them, my memory was only slightly better than the 3rd day with none. I'm sure it's a short lived effect and it may be confirmation bias, but it reminded me of how awful it was to have no meds or insufficient meds, where I couldn't keep anything in my head.
Another thing is that my tendency to depression gets shifted oddly. Without meds, I do nothing and feel no motivation to do anything except a sort of wistful longing that turns into hopelessness and depression the longer it goes. While I am on meds, I feel impelled to do something constructive every day, and if I don't act on that, my stability goes downhill fast. But I have to decide on something and do it, because if I just get sucked into something and do a project that takes several hours, I feel like that time was wasted (even if it wasn't) because I didn't CHOOSE to do the thing, my brain took over and wouldn't let me go until I was done.
And there's a thing that I am pretty sure is not related to meds, with work: I feel good when I have a pile of work to do, and I get stressed out when that pile starts to get down to nothing. I think it's because I feel worried that they'll run out of meaningful work and start assigning me useless busy work. If the work is meaningful I am okay with dedicating 99% of my brain to it for hours on end, it's not hard to focus, and I enjoy it. If the work is meaningless, I can't manage to dedicate more than 70% of my brain to it, and that would make me desperately want to quit because I'd be so distracted that the time would creep by like molasses and I'd spend SO MUCH ENERGY trying to stay on task. And I don't want to quit. So I hope they have endless meaningful work for me, but I worry.