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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?

#401

Post by _huayra_ »

Pretty much anything related to personal growth (however you define it) takes time to click, but it took a while to understand two things at a deep enough level to begin to make change:

* everyone has a set of habits that served them well during childhood, but may be maladaptive as an adult (e.g. getting angry is almost universal a sign of this maladaptive childhood habit rearing up). Book recommendation [0]

* the fear of hope is a key thing to understand when it comes to why people (myself included) hold themselves back. Taking the first step can feel terrifying because it demonstrates that one is responsible for creating one's own life. Book recommendation [1]

The only way out of this is to deliberately design your days so that you get the most out of them, even if it is fumbling at the start. Add in some times to relax here and there, but if you have a plan, it's much easier than staring at a blank Saturday with the vague goal of "I MUST learn JS/Rust/Go/Scala or my career will be over!!!" and then getting nothing done.

[0] https://www.goodreads.com/book/show/23129659-adult-children-...

[1] https://www.harpercollins.com/products/how-we-change-ross-el...

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

#402

Post by dannymi »

bonzini wrote: post #204
ofcrpls wrote: post #118

Fourier Transform. I'd been writing DSP code in C and MATLAB during undergrad while thinking I knew every possible aspect thanks to the deep study we had as part of coursework across all the transforms methods in our ECA & Communications coursework in India. Also, dad was a self-taught hands-on Analog electronics whiz whose day job was in Telecommunications Training, and I had uncles and aunts in the Telecom/Electron…

Interesting, Fourier transform has never been an issue for me but Laplace never clicked. I know it's kind of similar (convolution, exponential and all that) but I miss the connection with the frequency domain that is there for Fourier.

The frequency is the imaginary part of the Laplace parameter s (and the attenuation is the real part of the Laplace parameter s).

Laplace transforms work on systems with attenuation—that’s the main advantage.

Because the kind of transform was swapped out anyway, people used the chance to often only define one-sided Laplace transforms that only work for t > 0 (because as an engineer, thats the systems you want anyway).

There’s a direct correspondence between the (usual) one-sided Laplace transform and the (unusual) one-sided Fourier transform for that reason.

Since you usually have systems where f(t) = 0 for all t < 0 anyway, the distinction one-sided or not is not so important in practice for understanding.

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

#403

Post by zabzonk »

sureglymop wrote: post #181
zabzonk wrote: post #121

Earlier quoted context omitted.

I've always found OO programming completely natural. n fact, it's the only kind of programming i've ever really done - create a structure with data members, and then create functions to work on that structure. you can (and should) do this in low-level languages such as C and assembler. Of course, if you want to go the whole polymorphic route, i'd suggest using something like c++, but the key ideas are really structur…

I've always had a hard time because I was thinking.. why would I carry the performance hit of instantiating objects for a bunch of stuff?

you have to instantiate variables anyway. grouping those variables in objects simply makes your code more understandable - there is really no extra cost.

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

#404

Post by thewebcount »

machina_ex_deus wrote: post #220

Learning history / literature in school is important. I was a total STEM math nerd in school. I used to frequently complain how I don't get what's the point of it, or how it's a waste of time and I'm learning nothing. I still think the emphasis of school was off, but I get the point of it now. Stories are like code for humans. You can't tell someone what it means to be good or bad, or to give them a course in philoso…

I was fine with literature, but yeah, history, what a snooze-fest. Why do I care who fought what war 1,500 years ago and who won? It seemed like it mostly came down to a bunch of pompous elites having dick-measuring contests a lot of the time.

Then one day the teacher didn’t want to teach and instead showed an episode of Connections, and I was blown away. Learning about how and why our science and technology became what it is was something I could related to and seemed actually useful. I still don’t care for military history, though.

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

#405

Post by db48x »

screye wrote: post #339

Related : I have a request for the 1 major concept that has never clicked for me --> Can someone help me understand 'productive value' in an economy ? I have tried hard, and can't for the love of me understand what lies at the bottom of trade, what is the base value of assets / activity. It just doesn't click. Questions like: - Can a services based economy work if the consumers of the services weren't producing some…

I can answer two of those. Middle-men are useful whenever there is fan-out or fan-in. A producer wants to sell to consumers, so there is a lot of fan-out. The producer could get the consumers to come to the factory and to buy good directly, or they could go door to door, or they could use middle-men: retail stores. The stores buy the goods wholesale and take on the work of selling them to individual customers, in exchange for a portion of the total profit. Customers visit stores for the same reason, to avoid having to visit every factory for every producer of the goods they want. With time and effort saved on both sides, the stores benefit both the producers and the consumers.

The economy is not a zero-sum game because we are summing the value, not the prices, of the goods that are traded. If I grew wheat and you grew apples, then we can trade between us to mutual advantage, because after the trade we can both make apple pie (assuming we can find some cinnamon). The total amount of wheat and apples hasn't changed, but their value has gone up. Every trade involves two parties who must both believe that they will gain value by the trade. Of course it is possible for either party to be mistaken (or even deliberately swindled by the other party), but as long as the majority of trades have net positive value then the economy as a whole will be a positive-sum game.

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

#406

Post by rkp8000 »

DylanSp wrote: post #115

Matrix multiplication. First encountered it in high school, where the textbooks presented matrices without any real motivation, and matrix multiplication just seemed like a weirdly-defined operation. Once I got to linear algebra in college and matrix multiplication was presented as the way to compose linear transformations, it made a lot more sense.

A big one for me was realizing that a matrix times a vector returns a weighted sum of the matrix columns, with the vector's elements as weights. It's not particularly profound but it has definitely clarified my intuition around a number of matrix problems.

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

#407

Post by __s »

parasti wrote: post #38

One of the biggest realizations recently for me was realizing that a nearly all of software development is basically about turning a slow, manual process into a faster, automated process. Modern CI/CD stems from a bunch of shell commands that somebody wrote and manually executed to test an app and upload it to a server. Modern automated software testing stems from humans writing small test apps and running them to co…

In fact a well designed system I work on (database service) is built to give people sufficient monitoring & control that operators handle anything out of the ordinary until they get annoyed enough to automate it

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

#408

Post by josephcsible »

satvikpendem wrote: post #398
machina_ex_deus wrote: post #220

Learning history / literature in school is important. I was a total STEM math nerd in school. I used to frequently complain how I don't get what's the point of it, or how it's a waste of time and I'm learning nothing. I still think the emphasis of school was off, but I get the point of it now. Stories are like code for humans. You can't tell someone what it means to be good or bad, or to give them a course in philoso…

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'…

I agree in general, but for me it wasn't so much just having to read them as it was having to do a bunch of silly assignments based on them. My high school completely ruined The Great Gatsby for me that way.

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

#409

Post by faddypaddy34 »

alphydan wrote: post #347
ShredKazoo wrote: post #305

Earlier quoted context omitted.

As a white guy, I'd certainly encourage you not to worry about this -- if we're talking about an upper middle class, professional-ish activity, you can be fairly sure that all those white people feel self-conscious about their group being so white and would welcome you to join them. Anyway, I'd be interested to hear more about the psychology of this. I remember when I was growing up in the 90s and 00s in California,…

The better question to ask yourself (you the white guy), is would you join a group [insert som hobby like hiking] composed 100% of Cholitas. If yes, are you sure? if not, why not? *Not singling out Cholitas, but it's a group that may feel "other" to you.

The better question is would that group let a lone white guy join?

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

#410

Post by satvikpendem »

buzzert wrote: post #317

For me, it was the difference between “is” and “ought”. It sounds obvious when you first think about it, but I spent a vast majority of my 20’s with a view of the world filled with “oughts” instead of “is’s”, especially when it comes to things I can’t control. I.e., people “ought” to behave a certain way, versus the way people actually behave. The way companies/governments “ought” to operate, versus the way they actu…

Are you familiar with the is-ought problem? Somewhat related.

https://en.wikipedia.org/wiki/Is%E2%80%93ought_problem

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