What Does “Don’t Memorize!” Mean, Anyway?

“Memorize Everything!” was good organic chemistry study advice in 1952.

From the MIT Technology Review, a letter to the editor:

A Memorable Chemistry Final
There is only one final exam that i can date from my four years at MIT. In May of 1952, I took the final for organic chemistry, a course that I thoroughly detested. At that time, it took brute-force memorization to learn organic, for undergraduates were not yet taught to use basic principles to predict chemical interactions.

I was horrified to find that the final exam consisted of eight steps in a chemical process leading to synthesis of penicillin. I felt like a complete fool, for I had attended course lectures given by Professor John Clark Sheehan, who synthesized penicillin. In later years I would tell my students how important it is to understand what makes your professors tick, using my story as an example. My experience is burned in my memory, for I married my high school sweetheart on May 31, 1952. The organic final left me in very poor condition for the wedding, so I will never forget what Professor Sheehan did to me!

William L.R. Rice ’53
Fredericksburg, Virginia

On the other hand, “Don’t Memorize! Learn the concepts!” is a commonly heard piece of contemporary study advice, usually followed by dire warnings that flashcard-wielding memorizing zombies will eventually meet a terrible fate.  Two examples. First, Quora:

Do not just memorize reagents  (you will forget them as they have no context to you or the compound the the left of it.Don’t try to memorize….that is a certain recipe for failure. You’d be better of making data reagent lists/uses/ etc. for yourself and learn more than buying some prefabricated things at a premium and which don’t help.

Second, an article from the Clemson newspaper:

Don’t Memorize. The number one reason people find organic difficult is they try to memorize everything. This course is not about memorization. You can’t memorize hundreds of reactions, and you certainly can’t memorize Stereochemistry. Treat organic like a math course; work lots of problems and learn the process. Put the pencil to paper and draw out those mechanisms. Odds are there will be problems you’ve never seen on exams, so you’re much better off learning the processes.

To be fair, while both of these articles explicitly say, “don’t memorize”, if you read between the lines, you might be able to interpret both of these pieces of advice as saying, “don’t just memorize”, “don’t memorize everything“, or “success will require more than just memorization.”

Still, it’s easy to forgive students if they interpret, “DON’T MEMORIZE!” as, well…  “don’t memorize – EVER”. And that’s why when I hear, “don’t memorize!”,  I feel  a duty to correct and clarify.

I’m going to spend a few posts talking about this. But first, I wanted to understand what people meant when they said, “Don’t memorize.” What, specifically, do they advise people NOT to do?  

When People Say, “Don’t Memorize”, What Exactly Do They Mean?

A recent Reddit post on how to be successful in Organic Chem brought some “don’t memorize” advice out of the woodwork. I’ve highlighted some samples from this discussion.

Thread #1:  Commenter Major_Punishment [snippet] “Don’t memorize, practice, and when you think you’ve practiced enough, practice some more.” [link to full]

My Q to this commenter: “When you say, “don’t memorize”, could you explain a bit more what you mean? Is there something specific you would advise not to try to memorize?”

Commenter MikeJoeSchmoe: “Don’t memorize” is kind of a misnomer. The sentiment is more “know everything well enough that it becomes instinct and you can improvise.” The biggest difference that I’ve found between Gen Chem and OChem is that the former is much more formulaic (i.e. solve problem X this way; solve problem Y this way; etc.) The latter is like Legos where you learn about pieces and how they connect (i.e. how to make a primary alcohol, how to halogenate a compound, etc.), but it’s ultimately up to you to figure out how to make what you want.

Commenter Major_Punishment: Exactly, for the longest time I was confused/angry every time my professor told us to learn not memorize, but eventually you see patterns (some of which are the gamblers fallacy) and you can reason your way through most any mechanism though it may take a Brazilian tries.

Bottom Line #1: “don’t memorize” means, “don’t rote memorize a lot of reaction mechanisms without looking for patterns”.

Thread #2:  Commenter uhmareikuh: What you need to do is not memorize reactions, but think about EVERYTHING in terms of electronegativity, because really that’s all that organic is.

My Q to this commenter: “When you say, “you don’t need to memorize reactions”, what does that mean? Can you give an example of what “doing it wrong” means to you?”

Commenter uhmareikuh:  Your prof will present a rxn in lecture that you will write down and take into memory. Ok fine. Then you see it on the homework and you remember the chemicals and you think to yourself, this is easy!

Well, in organic, there are millions of different ways to cover a classic reaction through a ton of different looking chemicals and reagents.

So you get into the test, and you are looking for those chemicals you bore into your memory. They aren’t there. However, something kind of similar is presented (or maybe not, because some things that look completely different do the same thing sometimes) and you can’t work it out . This is because you don’t understand the overall trend and outcome in the reaction.

Bottom Line #2: “Don’t memorize” means that if you memorize just one example of a reaction, that doesn’t mean you know it. You have to be prepared to recognize what other examples of that reaction might look like. 

Thread #3:   Commenter Rugbykid9:  If you plan on taking the 2nd semester of it, please for the love of god don’t just memorize the reactions for the 1st semester. Actually learn them and understand how they all work.

My Q to this commenter: What do you mean by “don’t just memorize”? For instance, when someone learns about, say, dihydroxylation of alkenes, how would they learn it in a way that doesn’t involve “memorizing”.

Commenter Rugbykid9: What I mean by memorizing is basically just short term memory. For example you just memorize for the upcoming test and then it’ll never pop up in your head. This is what you want to avoid. You need to learn these things and commit them to memory rather then just knowing them for the short term.

My 1st semester professor told us that if we did just ‘memorize’ it would come back to haunt you in the second semester. He was 100% correct. It’s very easy to not even realize it but with practice you can learn it instead.

Bottom Line #3: Memorizing for the short-term purpose of a test (without understanding the concepts) will come back to bite you in the long term, because organic chemistry reactions and concepts are tested cumulatively. 

Thread #4:  Commenter Chobitpersocom: Focus on understanding, not memorizing. Treat it like puzzle solving.

My Q To This Commenter: What would be an example of something people try to “memorize” and do poorly at?

Commenter Chobitpersocom: Reactions and reaction mechanisms. If you understand the concepts behind them, you can logically work things out. Memorizing doesn’t help when you’ve been approached with something slightly different.

I mean it’ll help to memorize functional groups, but understanding and lots of practice is really what will get you good at Orgo.

What “Don’t Memorize!” Really Means 

Four answers in, and we’re at something that resembles a common theme.

 “Don’t memorize” doesn’t mean that bad things will befall you if memorize things like functional groups, pKa’s, abbreviations, or certain aspects of nomenclature, especially since memorizing these types of things is not a huge time investment.

When people advise, “Don’t Memorize!” they generally mean, don’t rote-memorize reactions and mechanisms with the goal of regurgitation in mind.  This is for two good reasons: 1)  because setting out to memorize all reactions and mechanisms is a huge time commitment and that time is better invested learning the common patterns, and 2) organic chemistry is not tested the same way as anatomy.  Look to understand the patterns and you will save time in the long term. One of the best ways to see these patterns is to do lots of problems. 

Spending a huge amount of time with the goal of being able to regurgitate where every arrow goes, without understanding the deeper concepts of electron flow, is learning organic chemistry in a shallow way. An exam written in a way that tests deep knowledge of organic chemistry will blow someone who prepares this way to F-ghanistan.

A Couple Of Caveats

One caveat. This advice makes the assumption that you’ll be tested on deep knowledge – a good assumption if you will be taking the ACS Organic exam, for example.

If you’re tested in a shallow way, you’re in luck.  Then memorization turns out to be a fine strategy for doing well in exams. And judging from comments, in some courses, this is enough.

A second caveat. Some reactions are presented “as is”, with very little mechanistic discussion. For example, oxidation of aromatic side chains by KMnO4. Or reduction of dithianes  to alkanes by Raney Nickel.

Or,  as has been the recent trend, covering olefin metathesis and palladium-catalyzed cross coupling in introductory organic chemistry classes without prior introduction to the chemistry of transition metals.

In these situations you have no choice but to “just memorize” the reaction. Sorry.