It's hard to deny that one's memory deteriorates before age 40. But does it really matter that much to job performance? I'm not sure, but then I'm not a profess

It's hard to deny that one's memory deteriorates before age 40. But does it really matter that much to job performance? I'm not sure, but then I'm not a professional software developer, so that might explain our differing views. I do have to disagree about the number of hours worked being a sign of mental degradation. I'd call that physical degradation, and to be honest, I'm able to work longer days now than when I was 30. Everyone's mileage will vary on that, though. For me, what dominates everything else wrt mental performance is that I'm much more efficient at learning things now than I was in grad school 20 years ago. Whether it's a new technology, a mathematical proof, or reading someone else's source code, I'm massively more productive than I was at 25. If anything causes me problems, it's that I enjoy learning new things too much, and I spend less time than I should doing the work that pays the bills.