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Comment by GeneralMaximus | Hacker News Reader

I hear you. I've always insisted on figuring things out instead of memorizing them.

Here's an anecdote: back at high school, my class was told to write all of the basic sine-cosine formulae 100 times. The homework was worth 5 marks. I found I could derive most formulae myself, so I didn't do the homework. The result? Not only did I lose 5 marks, I also scored badly on the test because it was rigged. You could only solve the test questions if you had crammed every one of those trigonometric identities. (I did manage to solve most of those questions, but deriving the formulae from scratch took time. The test consisted of a lot of questions, each of which was worth very few marks.)

This has happened to me over and over in the past four years, in both high school and college. And no, I'm not "gifted". I'm just an average student who likes to understand how things work.

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I've always had an apprehensiveness towards classes or jobs that require you to memorize things before you've actually encountered the necessity to do so. If you're paying attention while you're working through math problems, programming assignments, etc., patterns emerge and you quickly realize what constants are important, which programming methods you should remember the argument order to (or keyword/symbol names), etc.

I guess I understand (begrudgingly) the necessity to memorize something for a high school math test where you don't have the resources at your disposal to actually find the answers yourself, but in the "real world" where finding the information you're looking for is so quick and inexpensive, it seems like a waste to invest in something that might not be necessary. (Also, for some people who don't have the skills to think through solving those problems on their own, it could be a pretty big disservice.)

I can't even begin to remember how many constants, dates, formulas, names, etc. that I've memorized for a test and then promptly forgot.

The two aren't mutually exclusive. Just because you understand how to derive a formula doesn't mean that it's not useful to memorize it.

amen ... oftentimes a cache look-up is way faster than re-computation, and by developing your associative memory, you're effectively "increasing the size of your cache" over time, which is never a bad thing. some of the smartest people i know have incredible memories and are able to pull together memories from seemingly disparate times, places, and subjects to generate insights that are simply impossible to come up with by stubbornly deriving from first principles

Aye. That is what I do these days. But my long term retention rate for math formulae is nearly zero.

I just came home from a math exam. During the exam, I could recall almost every formula I had crammed last night. By tonight, I'll forget nearly half of them. In two weeks, I'll only remember 10% of the stuff I learned, and that too merely because some of those formulae were strikingly obvious or wonderfully symmetrical.

I guess I just have a terrible memory.

You're not alone in this department. Repetition is the key.

More: http://www.supermemo.com/english/princip.htm (the whole site is pretty decent at explaining the process of learning)

> And no, I'm not "gifted". I'm just an average student who likes to understand how things work.

The really smart thing to do would have been to both know how the formulae are derived, and also notice patterns in them that will help you remember them (symmetry, special cases, designing your own mnemonics, etc.).

Sure, smart people can do this, but you'll find many don't simply because they question its necessity. Or even simpler because it just isn't interesting and they could be thinking about other things.

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