I definitely hit my coding peak somewhere in my late 30s. I don’t know how much slower I actually am, vs how much less I care. For one, I care to not write code that I’m not going to use. I spend way more time planning, talking about, and mulling over the thing I want to build, and I generally get it right the first time. Maybe part of the lesson of experience is not being in such a rush. Second, I’ve written so much code that I just don’t care as much about that activity as I used to. When I’m properly motivated to do something I still feel quick and energetic. I’m learning ASL with my girlfriend and she’s frustrated that I move faster than her, at some 13 years her senior. Maybe it will catch up to me eventually.