[harperlee]

Someone somewhere (gwern? Xkcd?) estimated: if you think you will lose 5’ in the rest of your life searching for it, you can anki it and will save time, statistically, over the long term.

Something like grep can easily meet the mark.

[gwern]

Me, yes: https://www.gwern.net/Spaced-repetition#how-much-to-add

The XKCD comic you're thinking of is much more general^: https://xkcd.com/1205/

^ and not too helpful here because it assumes you know how much time something saves/costs - which isn't obvious for spaced repetition because the entire point is to dynamically adjust the timing & number of repetitions over the long run.