Ask HN: How old are you (optional) and what was the last thing that you learned?

[gravy]

Doesn't have to be tech related.

[scarface74]

44, a former coworker that I would go see once a year at a coding conference just passed. He was 47 and left behind a wife and three young daughters.

I learned never to take today for granted and don't put things off for tomorrow with your loved ones. Your job will send flowers to your family and then open up a req for your position. Don't put your job before your family.

[DuskStar]

24. Why nuclear weapons produce a double flash. I'd read that was a signature of a nuclear detonation (Clancy novels, sue me) but not why. Turns out it's because the shock wave is hot enough in the early stages of the explosion to become opaque, blocking light from escaping. As it expands, the shock wave cools and becomes transparent again, letting the light from the fireball inside escape.

[1mike12]

I play this game airsoft (like paintball) and I like to go especially on beautiful days like today. It's so much cardio and you don't even notice it. Anyways, this Canadian company makes these really innovative reusable bang grenades and I finally learned how to toss them just right to clear out rooms. In movies the badass hero makes perfect throws without even thinking. But turns out in real life having your gun in your main hand, pulling the thing out with your non dominant hand, pulling a pin, and then getting it throug an opening, while hoping and praying nobody gets the jump on you is really really hard. Before this I would blow myself up, or forget to pull the pin. Oops.

[Spacemolte]

So true, it really is amazing that you don't even notice the exercise when combining it with something funny/purposeful. I was in a milsim game some years ago, in a room at a military training site with my mate, and suddenly we see something thrown inside the room, and we just know that we gotta get out, so we scramble for the door only to get stuck shoulder to shoulder getting shot in the back by a guy in the window. The "grenade" was a brick .. :)

[potta_coffee]

The correct way is to have your team cover you and throw with your dominant hand.

[zck]

33. Most guitar tabs for The Beatles' Norwegian Wood are wrong -- they have the intro accurate, but it's not the same as the part played under the lyrics.

And it's not just that the song is played on a sitar -- even the sitar isn't mirroring the intro to the song through the lyrics. Look at, for example, this tab (https://www.guitartabsexplorer.com/beatles-Tabs/norwegian-wo...), which explicitly says "Use same guitar pattern under solo voice". Now listen to the song (https://www.youtube.com/watch?v=OYs02z35F24), which doesn't use the same pattern under the voice. It's a good accompaniment, but it is just different.

[seanhunter]

Many (and possibly most) guitar (and bass) tabs for songs are (unfortunately) wrong. Likewise very many chord boxes and often the chord names themselves are wrong. There are notable exceptions (eg "Standing in the shadows of Motown" - the transcription of James Jamerson's basslines is genuinely superb).

There's really no substitute for listening really closely to music you really like and figuring it out for yourself. I have boxfiles of transcriptions I did and if nothing else, it improves your ear to the extent you get faster and faster not only at doing transcriptions but at learning music generally.

[DEADBEEFC0FFEE]

47m, I was reading about installing Kubernetes the hard way, when I learned my 9yo son is a badass sniper in Fortnite.

[morog]

38. Eveyone spent 4 months inside their grandmother (as an egg inside their mothers fetus)

[geetfun]

Wife and I were just talking about this and how this is a great example of how decisions made in one generation can have consequences that span multiple generations (eg. Eggs, where one’s family immigrated to, etc)

[Raed667]

26- I learned that my body is not as "unbreakable" as it was ten years ago

[maccard]

If it helps,im the same age as you, and I learned my body wasn't as unbreakable as I thought it was when I was 16. Hope it works out for you. What I've learned is our bodies are impressively good at fixing the things that go wrong with them

[flashgordon]

39. I feel the same way as you!

[drakonka]

29; the last thing I learned was the importance of sleep, which I've heard about before but never really internalised until now. One of the coolest parts of this that I learned is how in certain stages of sleep you get this stuff called "sleep spindles", the activity of which is associated with memories from your short term memory buffer in the hippocampus being relocated to your long term memory in the cortex. This sleep spindle activity can be measured in pulses in your brain during this stage of sleep, pulsing between the hippocampus and the coretex at a rate of 100-200ms. Upon waking you are left with longer term recall of what you had learned pre-sleep, plus your short term memory buffer in the hippocampus is now free to learn new stuff. Our brain is so exciting!

[jpindar]

Not to get emotionally involved with a product that could be turned off at any time. And that just because a business is more popular and better technically than it's competitors doesn't mean it doesn't have problems behind the scenes. And on a related note, if you don't have something downloaded to your own hard drive, you don't really own it.

[vidanay]

46, I took Discrete Math I & II this past spring. It wasn't easy. Last math class I has was (failed) Calculus I in 1989 and (failed) again in 1990.

I got a B+ and an A- this time, but I probably put in 30 hours per week studying and doing homework.

[kup0]

I actually enjoyed Discrete Math and Calculus as subjects, but the professors I had were so bad that once I was out of there I never really revisited them. I've had that happen with a few subjects, unfortunately. Now, years later, I've been wanting to revisit the subjects again.

[hiram112]

Just out of curiosity as I'm probably closer to your age than I am to the majority of folks here, are you taking these classes as part of a grad program in CS or related?

[benjohnson]

44 - Learned how to use a 4.25 inch grinder to strip apart a safe that I can't move. I now realize that padlocks are just there to keep the honest people honest.

[fbomb]

55. Just stumbled across a philosophy course online. I had always thought of philosophy as archaic, useless and boring. I could not have been more wrong.

[srik]

Could you provide a link to the course. Id like to check it out.

[tjansen]

42, Machine learning. I discovered Coursera for me and worked through a number of courses. People say that learning is getting more difficult as you get older, but so far it is getting easier for me. When I was younger I didn't have the patience to learn something if I had no immediate need for it. There were distractions everywhere. Now it is much easier for me to focus on a single thing.

[wastholm]

48. Started learning music theory, so far by means of parts 1 and 2 of "Music Theory for Electronic Music" on Udemy. I dabbled in music in my 20s but never really knew what I was doing so it's amazing fun.

[52-6F-62]

Oh if you missed this you should check it out https://news.ycombinator.com/item?id=17638067

[ninedays]

32. I learned that humans can cry because their pet is dying. I cried because my best friend cat died (14 years R.I.P.) and it felt like it was my cat. I know it sounds stupid but this was a life lesson to me.

[squirrelicus]

31. In Java, this code can spin forever if a different thread changes this.done, and it's not a "volatile" member.

while(!this.done){ Thread.Sleep(1000); }

The more I learn about Java, the more I'm shocked at how mostly-identical it is to C#. Except C# is clearly superior in the details. I expected to find something java did better, but I'm coming up short.

[h2j24]

One interesting article I read had an interesting point: one thing Java does better is to use type Erasure. This was surprising to me because reified types are often touted as one of the best things about C#. The author's argument was that type erasure made implementing different type systems on the JVM easier, because type erasure isn't as strict, which makes the JVM a more attractive language target than the CRT.

[theli0nheart]

31. I just learned how to make soap in Dwarf Fortress.

[gota]

32 (and just learned about Competitive Analysis) but I wanted to say that learning how to make stuff in Dwarf Fortress is always rewarding in a very deep sense. I have no idea why, but every new mechanic mastered seems to multiply the possibilities of fun (and dwarf fortress 'fun' also)

[blue_tongue]

49, TIG welding for bicycle frames.

[JoelSanchez]

24, how to create a k8s cluster with kubeadm using cheap VPSs. Also, sea waves are more dangerous than I thought

[Immortalin]

How are you handling node additions and removals? Terraform?

[RickJWagner]

53. I'm learning to play the banjo and solve Rubik's cube. (I can solve it, but still need a cheat-sheet.)

I learned to juggle at 50. My plan is to try to stave off mental decline by learning new stuff.