There are probably so many noob-facets to this question that it's not even funny. Basically I've never fully understood memory usage, despite being a professional digital artist for many years.
In this case, I'm trying to make sure that Blender is using as much memory as I can give it. My computer has an absurdly large amount of RAM, well over 64 gigs. I've gotten the impression that this is "overkill", but I definitely find Blender slowing down when I do high-poly sculpting, or when I apply complex modifiers.
I've set the Memory Cache Limit to the maximum, 32768 mb, but I'm wondering if there's some other obvious thing I should be doing to leverage the massive amount of memory that I have available. Or maybe the things I'm trying to do are more dependent on the CPU or other factors? I'm running Windows 10, if that matters, and I've got a 64-bit version of Blender.