That's what I'm thinking about too. Most directories are describing what's already available for the computer to extract: the place of something being created,

That's what I'm thinking about too. Most directories are describing what's already available for the computer to extract: the place of something being created, the time of it, the source where it came from (e.g. who sent this as email attachment). Only a minority needs to be explicitly added, like emotional meaning ("my favorites"), or external organization ("experiment 1", "driver's licence"). While we can't use the computer for the latter, it's nonsense that we leverage computers so little for the former.