I am either too stupid or too lazy to remember everything. Or my version of ADHD specifically restricts my ability to remember things, or to have sufficient energy to engage daily with the process needed to memorize information (e.g. build and review anki decks).

I gave up on Anki. I abandoned org-roam and switched to trillium with very simple summaries of hand written notes. I don't summarize articles I read, I simply save them to my bookmarks with good tags.

I might be stupider now, I don't know. My mandarin improves at the same pace it did before, when I was doing daily flashcards, according to my mandarin teacher. Except now I don't have the torturous Todo item of "do mandarin flashcards" weighing on me every day, or the huge catch-up if I miss even two days (again, I am stupid - I usually miss 20% of my cards, daily. Often the same cards. I have forgotten the same word over 100 times.)

But, the other day I went to trivia in Cambridge UK, where I was probably the dumbest person in the town and almost certainly in the pub! And everyone was answering very interesting questions with correct answers, about geography, history, science, even the geography of the Americas which as an American should at least have been something I knew better than my British colleagues! Nope. It made me regretful that I grew up in suburban America and didn't get a nice bit of background education like Europeans do, or maybe for me being dumb or having ADHD. It I always admired smart people and I always wanted to count myself amongst them - it's why I brute forced my way into engineering by picking the lowest barrier to entry bit (frontend) and gritting my teeth and smashing pencils through hour after hour of tutorial and project until I finally had a portfolio I could get hired off of. And still almost always, dumbest person in the company (there have been less productive than me, though), and no idea how to change it. I'm wondering again if there's something I can do to be smarter.

I am fascinated by the promise of zettelkasten, spaced repetition, fish oil, whatever, but none of it seems to deliver!

People should just stop worrying about their Anki backlog. The truth is, every little bit you do helps, even just one card a day. That "backlog" is just telling you that you are falling short of perfection wrt. keeping the whole content of your deck securely memorized. You'll still be able to recall the bulk of it as long as you keep a reasonable routine.

As a fellow sufferer of same issues, I sympathize.

You are too hard on yourself though.

It is like a running race, when we are required to carry 50 Lb bags on our backs, while others are running freely.

At some point we need to accept and not worry too much!