[tvanantwerp]

Probably true if you can't remember how to write if/else or a for loop. But it's very useful for the bits of knowledge that you might not be needing all the time. Don't know how many tweets I've read from developers saying things like "I've been coding for ten years and I still have to Google this one particular thing". Those things are perfect for flash cards.

Example: I am almost never in need of grep. But sometimes I want to know which files in my project contain some string. Never could remember the right flags and order of arguments until I made it a flashcard--now I don't have to Google it anymore on those rare occasions when I need to know. Using flashcards for lots of little things like that really speeds up development; my cognitive switching costs are greatly diminished.

[bluGill]

Does it speed up development? Or slow it down because you are reviewing things you rarely need instead of doing useful work? Sure in the moment it speeds things up, but over time it slows things down since you spend time learning things you might not need again.

[Jtsummers]

This would depend on when you spend your review times. I do mine 2-3 times a day: morning with my coffee, around lunch, evening after dinner. Times that are otherwise mostly "idle" (if I'm doing anything else, it's browsing, reading a book, or watching a show). I do sometimes put together cards during the workday (I need to get back into this habit) after looking up something I don't know or couldn't recall but thought was worth committing to memory.

In the end, trying to remember everything would be silly and largely a waste. But memorizing those things that are common (but not daily) pain points would probably be an improvement over not. OTOH, I'm not going to quantify my time sufficiently to be able to provide clear evidence that it really speeds up my work.

[kazinator]

One problem is, "might not need again" is self-fulfilling. When you're developing something new, you mostly rely on what you happen to know.

What you know is a Turing-complete subset with all the platform escape hatches you need, so you're able to get your stuff working.

[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.