I've been wondering some lately about what the world would look like
if the competent use of spaced repetition software was as commonplace
as something mundane like high school algebra. For the purposes of
this thought experiment, I'm not increasing the general sanity of
people or civilization (so e.g. people won't magically start
memorizing important things). They would just have "virtuoso skill"
(as Michael Nielsen would say) at using spaced repetition software.

Some ideas:

* Reputations have the potential to be more solid and precise. Someone
  who made a thoughtful comment on a blog post could rely on it being
  remembered far into the future. Someone who flouted a social norm
  wouldn't just be remembered as "weird" but would actually have the
  precise behavior documented and remembered. Michael Nielsen gives
  the example of memorizing specific reasons he doesn't want to
  collaborate with certain people.

* I want it to be the case that people can hold more ideas in their
  head at once, and for there to be more "serendipitous" discoveries.
  But I'm not actually confident this will be the case, seeing that
  people don't even have basic traits of competence (like searching a
  forum before asking a question).

* For social scientists: given access to people's SRS decks, it would
  be possible to tell what really matters to people, for the long
  term.

* I think software like to-do lists can make use of softer deadlines,
  which act like a snooze button on an alarm clock. Right now when
  setting up social meetings, a meeting can still fall through if one
  side suddenly gets busy, and once that happens the meeting may never
  happen again (because the scheduling is brittle).

* Currently websites like Hacker News, reddit, and LessWrong act like
  news feeds where the latest content is at the top, and after a few
  days that content gets replaced on the front page by even newer
  content. While there are some manual efforts at reminding people of
  "timeless content" (like best-of lists, FAQs/subreddit wikis, the
  LessWrong annual review, other forms of curation, people linking to
  old posts in discussion, old-timers/regulars linking to identical
  previous discussions), it seems like there aren't many automated
  ways to remind people of existing discussion. The only thing I can
  think of is the related questions that show up when you go to ask a
  question on Stack Exchange and Quora, and Facebook's "On This Day"
  feature. If websites took spaced repetition seriously, there could
  be a way to non-intrusively remind people of posts they've read or
  liked in the past.

Things that might prima facie seem to improve but where I don't expect
improvements:

* Compared to before the arrival of smartphones, something like the
  ability of remember facts that can be looked up quickly, or
  remembering phone numbers, addresses, driving directions, isn't as
  important.

* Remembering the physical location of objects. (e.g. where are the
  car keys?). I think this sort of spacial information of things that
  change frequently are hard to describe and put into SRS.

A reverse point of comparison might be: how would the world look if we
didn't have robust ways to schedule things to happen at a specific
time? In other words, the world suddenly lost the ability to use
calendar software, alarm clocks, timers, etc. Spaced repetition
provides a much more "squishy" kind of scheduling (I sort of think of
the analogy of spaced repetition to date-based scheduling as machine
learning to regular programming).

Andy Matuschak writes about a related idea and calls it "spaced everything":
https://notes.andymatuschak.org/Spaced_everything

See also gwern's idea of spaced review of notes and other media:
https://www.gwern.net/Statistical-notes#program-for-non-spaced-repetition-review-of-past-written-materials-for-serendipity-rediscovery-archive-revisiter