How does capability change with age?

I don't think it's age.

Keep in mind the fact that the past year has been anything but conducive to normal productivity. I've experienced significant cognitive impairment, mostly due to stress, but busy-ness has been a huge factor as well and I've had to force myself to disconnect and focus on one thing. (This assumes you have no sleep issues which could explain what you're experiencing). I have a couple of quotes I refer to occasionally: "Complex thinking and problem solving is like a brain workout - the neurons live longer. Complex meaningful work increases capacity ... can be maintained late in life." And: "The number one factor affecting brain health is physical fitness measured by VO2 max".

Here's a good resource on burnout: https://www.npr.org/2021/03/08/974787023/burnout-isnt-just-e...

I'm older than you and would like to suggest that creativity/inventiveness is more of a frame of mind combined with many inputs. Read books and articles to cover the adjacent possible and the ideas will come.

I think we all need a vacation.

It seems you may need a break or a change of pace. You are only done if you decide you are done but if thats your decision it is likely that you’d go back on it in a while. Are you in a financial position to take a break, a ‘lesser’ role or work P/T?

Do you feel bored with it all? Maybe you need to concentrate on something else to give your brain a break and a resolution would emerge naturally.

I burned out a few times and it all came back eventually but am now careful not to go overboard again so I take it easy with work while having a better life outside of work. I also have a family and a 3 year old now so priorities changed as well. Whatever you do take it easy on yourself

Things are changing so fast that it’s likely for all of us to go through trying times but no, we’re not done at 40 or even 50. We just don’t have endless energy and time as we had when we were 20, and different priorities too, that’s for sure. Cheers

I have found overwork has caused the symptoms you describe, but not so much getting older. As a developer in their early 50s, I have certainly noticed becoming slightly slower, but in no way less creative. I have seen colleagues work effectively well into their 60s, but I suspect this is different between people.

This is not age. Basically you stopped doing deep work (programming and learning) and move into doing shallow work (emails, meetings ,etc). But this a natural step of promotion.

The problem is that the shallow work now occupy most of your time, and since you are not doing deep work, you deep skills decay. The decay created a gap between what is expected from you, and what you are current level is.

Another issue is the great acceleration of new tools / new tech , which occur both in breath (a lot of new tools) and depth( each tool is more complex). This acceleration contribute to the imposter syndrome, since you do not invested enough time to become expert in the new tech. I.e. you were promoted based on you skills with the old tech.

What you must do, if you want to close the gap, is use your free time to do more deep work.

I'm only in my 30s but I'm able to do things I never could 5 years ago.

Their was a very good atlantic article about decline posted yesterday, I would hope by the time I get to 60 I'd have the funds to hire people to work on my side projects. If only to hop into the code myself to fix things.

I very much hope I'm still programming in my old age