...how do you reconcile the power of working memory with the limits of human capacity?

Some people have more than others. It's a muscle, just like everything else. Use it and it builds. Neglect it and it atrophies.

I personally have a terrible memory with almost zero ability to remember dates, names, or quotations. I know the way is not rote-memorization, but the only thing that seems to fix this problem is when I blunder and make incorrect assertions when conversing with others.

Well, there's your ritual. Funny thing - I write notes, but I never read them. However, the act of writing them cements their content in my memory. If it doesn't, going back and reading my notes does not jog my memory. It's a ritual, not a reference.

I only remember the things that are interesting to me, by and large. On the plus side, I find many things interesting.

Yogi Berra misremembered lots of things. It made him famous. You could do worse.

One experiment I have been trying is to organize references on topics that interest me, using Mendeley in the case of hard-science topics and org-mode (Breaking big topics into lists upon sublists) for more general topics. I have friends that set up personal wikis for information pertaining to their hobbies, too.

If I'm doing research for a screenplay or novel or something I really need to go digging for, I use Novamind and have done since 2003 or so. Learning curve has gotten steeper, though. Using it, on the other hand, is a really good way to cement things in your head… and give you something you can reference later.