Ask HN: I'm 40 and feel my mental ability declining. Programming seems harder.

I feel this. I've found there are a number of possible causes. The most common one with the biggest impact is not getting enough quality sleep, as sleep quality often declines as you age and under stress (life is most stressful in your 30s and 40s). Restrict your caffeine intake and improve sleep hygiene, it makes a big difference, as poor sleep affects short and long-term memory, cognitive speed and mistakes.

> some hardware registers were being initialized in a procedure that was allocating working space for a numerical part of the program, because that's here he happened to open the log file for the first time, and he wanted the logging from the hardware registers to be the first thing in the log file, before he logged the fact that the memory had been allocated successfully.

To be fair (haha) I went from writing super organized code with loads of concise, well-documented files to writing code just as you describe when I started designing hardware and writing more complicated embedded firmwares. For whatever reason, hardware initialization boilerplate doesn't like to be spread out or organized. As soon as you try your code ends up breaking outright or becoming a vastly more complicated, gigantic mess.

It's because the hardware is soooo specific and we as software developers want to make interfaces that are as generic, high-level, and re-usable as possible. Example: You can't just write a function that takes two pin numbers and initializes I2C on them so you can talk with some module. You usually have to know--ahead of time--which two pins you're going to be passing to that function (so the types match; because each pin has its own special type haha) so the function can initialize the correct I2C bus on the chip (in the right way)... Which immediately makes such a function non-generic and kinda pointless since you'll never be able to re-use it in anything else for any other purpose. You quickly get into the habit of saying to yourself, "Why am I making this a separate function again?"

Also, the order of operations matters so much more in embedded stuff than it does in regular software. I could totally see the situation where you want to initialize logging immediately after initializing some hardware because you want the logs to reflect values that you only happen to have available during initialization... You don't need them after initialization so why waste precious memory keeping variables around just so you can log them later? Just setup the logger in the same code, write your variables, and be done with it!

Makes sense, right? Hah! Only in the world of embedded firmware!

Sharing my own anecdata: my Oura ring shows that on days I drink, RHR is 10bpm higher and HRV about 15ms lower. Exercise has a huge impact on sleep quality too.

My theory is that when you're young, your body has a much wider margin for error. A few drinks or sloppy exercise routines never seemed to impact my work. As I've aged, the margin has shrunk, and now there's a measurable effect that I can no longer ignore. Aging is in itself a handicap, but now after too many drinks, the next day both my cognitive sharpness and motivation to even care about shoveling bits around a network have declined.

Now I need to actively stack the deck in my favor, rather that engaging in behaviors that further handicap myself. So that means exercise, a sleep routine, zero alcohol most days of the week, reducing stress, all that goddamn stuff I never had to worry about ;)

Another way to think of it is this: at 40 or 50, can you afford to be lugging around a 20% RHR penalty all day? That will surely come home to roost, probably in the form of atherosclerosis. Remember the most common clinical presentation for a heart attack sufferer is not chest pain, but being dead on arrival.

I bring this up because it's worth nothing that our bodies and minds are remarkably good at covering up problems until far too late. When you get those early warning signals (high RHR, feeling of cognitive decline, etc) trust your body, be proactive, and employ countermeasures.

It's not normal decline at 40. You have a few decades more of programming if you want them. (I'm calling that out first because you put it in the HN headline all the 23yo founder techbros will see.)

Get a doctor visit to start addressing your concerns, like you're determined to fix it. And you mean actively fix it, not make a notation in your record and plan to do another checkup in a year.

If you WFH, make sure don't have CO2 or other air quality problems.

Make sure you're exercising, getting solid sleep on a regular schedule, maybe cutting out caffeine, and maybe ask doctor for nutritionist referral.

Also consider that the problem might be motivation. Maybe you see nothing interesting or worthwhile in porting someone else's hugely complicated API bureaucracy from one language to another.

"I struggle to hold more than about 2 levels of this call stack in my head. By the time I'm down in the weeds I've forgotten what I'm doing, what the purpose of the actual API call is."

I started using paper notebook/pencil to go down function call trees.

It helped me immensely.

I am in my late 40s and as another commenter mentioned this could be because we have more responsibilities and not necessarily cognitive decline.