Installing from scratch sounds scary, but I get how it would teach me things I'd actually like to know, like what is needed to run a system. It just seems so daunting, since at this point I don't know what is needed. But the Debian netinst sounds like the place to start, then.

(It also may be better than trying a completely distro in that after trying a couple of distros, I'm wondering if I aren't actually completely and utterly happy with Ubuntu and how it works.)

Thanks muchly for the advice!