alt Hacker News> Think more stuff like "find the angle of lines defined by (x-4y-1=0) and (x-y-2=0)", "write the number 2026 in base 7", "solve an equation sin^2(x) - sin(x) = 0".
> I plucked these from our country's high school final exam from this year. Back when I was in high school, I did mine in 60 minutes without an error when the time limit is 150 minutes and I intuitively immediately knew how to approach each task since the moment I saw it. Also all needed formulas are supplied, you don't need to remember any of them.
It seems like with just a little bit of doing it again, you'd be back at the level you were though. Especially if you can do it with formulas right. You would be slower for only a very short amount of time. All those things are in my view if you understood them at some point in your life, you will understand them to the exact same extent with just a little bit of reminding. I would say with most of those concepts, it would take less than 1 hour to be back at similar level. Like for instance number in another base etc.
Depends on the complexity of the task. That's what I tried to hint at by also mentioning college-level math. For the high-school level tasks yeah, couple of hours and I'd be as fast as I was in high school again. For the number in another base it could be as quick as less than 1 hour as again that's a simpler task than the other two.
For derivations/integrations it'd take more time. Less than what it took me to learn them in the first place, for sure. But still a lot more than 1 hour.
Cause I forgot how to "do them" in the first place, which is what the discussion was about in the first place. I still know the "theory" behind, so I can "figure it out" if needed without needing anyone to "instruct" me, or needing "classes" to learn how to do them. But essentially all the "practice" I had back then is forgotten.
And again the same goes for code and technology knowledge, which is what the discussion was about in the first place.
As a senior developer with 10+ years of experience I've already encountered situations where I needed knowledge I knew I had at some point, but already forgot. In my case as a backend developer working for the same company for 5+ years my favorite example is payments processing. There are tons of special/edge cases - e.g. how a failed recurring payment during a subscription is processed. That's something you set up once, then don't touch for years, and suddenly need to study again if a change is needed. How a subscription goes "past due", what you can do in that case, what your code actually does, how it reverts to correct state once a retried payment follows through, what options you offer a customer if his payment method expired and he wants to switch it, ...
And this is also a good example why "domain knowledge" and "code ownership" is a good thing in larger companies. Because under usual circumstances I don't have to deal with these, cause we have a dedicated person who's maintaining the payment-related code. I only fill in in urgent cases happening when he's on vacation.
And juniors designing stuff like this AI-first without properly thinking about all these cases won't learn all the edge cases this flow can contain. So if something goes wrong, you end up with nobody who has the "maintainer experience" for that code - you don't have the one person who is knowledgeable about that topic - everyone in your company is in the same spot as me - having to research the topics again to understand them enough to be able to debug the incident which happened.