Have you ever seen a programmer who really understands C going to stackoverflow every time they have to use an fopen()? Memorization is part of understanding. You cannot understand something without it being readily available in your head

I wrote a long answer, but I realised that even advanced C users are unlikely to have memorised every possible value of errno and what they all mean when fopen errors. There's just no point as you can easily look it up. You can understand that there is a maximum allowable number of opened files without remembering what exact value errno will have in this case.

Right, and a lot of them probably got that understanding by going to stackoverflow every time they needed to use fopen() until they eventually didn’t need to anymore.

In the book days, I sometimes got to where I knew exactly where on a page I would find my answer without remembering what that answer was. Nowadays I remember the search query I used to find an answer without remembering what that answer was.

Yes, I have. I do it too, even some basic functions, I would look up on SO.

You really just need to know that there's a way to open files in C.

I don't think you can reach any sort of scale of breadth or depth if you try to memorize things. Programmers have to glue together a million things, it's just not realistic for them to know all the details of all of them.

It's unfortunate for the guy who has memorized all of K&R, but we have tools now to bring us these details based on some keywords, and we should use them.

I still look up PHP builtins often because they're so inconsistent. What comes first, the needle or the haystack?

> because he had a photographic memory and just so happened to leaf through a book containing a required proof

It makes for good rumours and TV show plots, but this sort of "photographic memory" has never been shown to actually exist.

Huh, TIL [0]. Thanks. There are people who can perform extraordinary memory feats, but they're very rare and/or self-trainer.

[0] https://skeptoid.com/episodes/542

>His photographic memory manifested itself early — he would amuse his parents’ friends by instantly memorizing pages of phone books on command.

https://medium.com/young-spurs/the-unsung-genius-of-john-von...

I dunno, I went to a high school reunion last year, and a dude seemed to know people's phone numbers from 30 years ago.

If he could remember that sort of thing, I can believe there are people who can remember steps of a proof, which is a much less random thing that you can feel your way around, given a few queues from memory.

Plus, realistically, how closely does an examiner read a proof? They have a stack of dozens of almost the same thing, I bet they get pretty tired of it and use a heuristic.

I think many people who grew up before cell phones remember phone numbers from the past. I just thought about it and can list the phone numbers of 3 houses that were on my childhood street in the early 2000s + another 5 that were friends in the area. I remember at least a handful of cell phone numbers from the mid to late 2000s as friends started to get those; some of them are still current. On the other hand, I don't know the number of anyone I've met in the last 15 years besides my wife, and haven't tried to.

When I was in university, in my program, the most common format was that you were allowed to bring in a single page of notes (which you prepared ahead of time based on your understanding of what topics were likely to come up). That seemed to work fine for everyone.

I have a colleague who does that.

My students then often ask me to do the same, to permit them to bring one page of notes as he does.

Then I would say: just assume you're writing the exam with him and work on your one-pager of notes, optimize your notes by copying and re-writing them a few times. Now, the only difference between my exam and his exam is that the night before, you memorize your one-pager (if you re-wrote it a few times you should be able to recreate it purely from memory from that practice alone).

I believe having had all material in your memory at the same time, at least once for a short while, gives students higher self-confidence; they may forget stuff again, but they hopefully remember the feeling of mastering it.