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Ask HN: Concepts that clicked only years after you first encountered them?

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Re: Ask HN: Concepts that clicked only years after you first encountered them?

#641

Post by umarniz »

Self fulfilling prophecy.

It took several near burn-outs and tons of hours of my life lost due to frustrations before I truly understood this. The world is what you want it to be.

Hopeless because everyone in the world is so selfish? You create the world you live in. Live selfless and see the world transform around you.

Frustrated you have to constantly interfere to make someone good at their role? You have to yourself believe they are the best in that role and then see them flourish.

Afraid your relationship might not workout? The fear itself will make your worst thought a reality.

Your life becomes extremely easy once you truly understand the world is what you believe it to be.

Note: There are of-course strings attached to this concept, but understanding the power of this is life changing.

Re: Ask HN: Concepts that clicked only years after you first encountered them?

#642

Post by pizlonator »

My top ones:

- abstract interpretation. It was at least a year after I first heard of the concept that I grokked it enough to try to write my own, and it wasn’t until many goofy failed attempts and something like 6–7 years that I actually understood it enough to write a good one. And then it was another 5-6 years before I understood the theory well enough to understand abstract interpreters designed by others. So, like, that took me more than a decade to understand. Maybe I still don’t fully understand it.

- SSA IR design. It’s so easy to understand the facts of what SSA is, and it’s not that hard to use an SSA IR designed by others. But it took me over ten years from when I first read the papers and did my first attempt until when I actually got it. And I still feel like there are aspects of SSA that I don’t fully understand.

Re: Ask HN: Concepts that clicked only years after you first encountered them?

#643

Post by mekster »

czx4f4bd wrote: post #243
rolenthedeep wrote: post #110

It took me an embarrassing amount of time to fully grok what object oriented programming really means. It's one thing to have someone tell you what an object is, but it's another thing entirely to build a fully object oriented system. I remember what made it click: I was designing an animation system, which had a bunch of different interdependent moving parts. Once I started treating each part like an object and lett…

I didn't fully grok OOP until I saw how composition and dynamic dispatch can be used in real code to create abstractions and flexibly swap out different implementations for your interfaces. You could build a chatbot that supports Discord, Slack, and IRC dynamically at runtime, or a web app that can use multiple different database engines, or a social network with multiple types of posts that can all be rendered in a…

Examples totally do suck.

A class Animal is inherited by Dog class that barks. That's like the total opposite of what any practical example can be and people confuse how that's even useful.

Re: Ask HN: Concepts that clicked only years after you first encountered them?

#646

Post by sergiomattei »

lumb63 wrote: post #510
satvikpendem wrote: post #398

Earlier quoted context omitted.

Regarding literature, I'll give an opposite opinion. Being forced to read the classics in school led me to not caring about them at all because I just couldn't relate at all, I had not had the requisite life experience for them to make an impact on me. Now, being an adult and having the life experience, reading them again makes me think more deeply and I can actually relate. So I think in school, we actually shouldn'…

Not only this, but also the impact having to read something has on enjoyment. There are books like To Kill A Mockingbird that I didn’t care for in high school simply because I had to read it. When I revisited it years later of my own volition, I enjoyed it greatly.

I’d say this is by design. Exposure, not enjoyment.

There’s a number of classics I read at the time that I didn’t enjoy until adulthood. Reading them early on gave me a framework for understanding them later on in life.

Re: Ask HN: Concepts that clicked only years after you first encountered them?

#647

Post by supernova87a »

Quantum mechanics as continuous probability distributions.

It took me about 3 tries in taking QM classes to learn and understand that the whole thing was about continuous probability distributions (at least, the beginner, static stuff). And finally to understand how to understand what continuous probability distributions are, and how to use them.

Re: Ask HN: Concepts that clicked only years after you first encountered them?

#648

Post by eternalban »

rzzzt wrote: post #30
robg wrote: post #8

The autonomic nervous system and the adrenal cortex. Homeostasis is taught as a textbook fact, the body reverting to a baseline over time. What’s not taught is how much the impacts of daily life events drive a continuous stress response. Fight or flight is not just a reaction to deadly threats. It’s active every moment of every day to ensure survival. The adrenal cortex is always active, to traffic, your boss and col…

"Understanding Stresses and Strains" from 1968 presents a good depiction of the mechanism with familiar-looking cartoon characters: https://archive.org/details/understandingstressesandstrains The caveman pressing the alarm button is something I think of a lot.

I had to see it. Thanks for sharing.

Re: Ask HN: Concepts that clicked only years after you first encountered them?

#649

Post by DrJokepu »

coffeebeqn wrote: post #199
khaledh wrote: post #140

YAGNI and KISS. When I was a junior developer I used to overthink and overdesign solutions, most of which was never needed. It took many years and a lot of battle scars to realize that less abstraction is more. Today I see a lot of juniors do the same mistake and I ask them to revise their designs to keep it simple.

I use the rule of threes to kill off any premature abstractions. ie. Don’t think you need to make this generic if you have one or two different variants of it. Most often it’s one- so it’s very easy to see that you’re just solving imaginary problems at this point. Each abstraction has a mental cost for reading and understanding the code so I try to be sparing. Too many code bases in my youth were a nightmare to navig…

That being said, sometimes a good abstraction can really simplify a complex problem by dividing it up to a set of smaller sub-problems. In such cases, the abstraction is worth it even if there is no reuse. As always, rules like this have to be interpreted in a context.

Re: Ask HN: Concepts that clicked only years after you first encountered them?

#650

Post by eternalban »

JanisErdmanis wrote: post #242

Superconductivity. I did four PhD projects regarding superconductivity properties at nanoscale without really getting hold on the concept. For instance, how zero resistance is related to cooper pair tunnelling and BdG Hamiltonian. Only when I was forced to write introduction a month before my thesis submission I gave my best last try for the farewell and it clicked. Note the title of my thesis “Quantum effects of sup…

Would love to read that paper but search is not turning up any papers with that title for me. What's the exact cite?
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