12 years is the middle years for a career programmer. Enough to know what patterns aren't serving you, and enough to know that there is still a bunch to learn.
Middle years!? How long are these "middle years" supposed to last? I'm 22 years into my career and there's no way I've hit the mid point yet. It still feels like a joke to have a job title with the word "senior" in it.
How long have you been programming full time though? I find too many people on HN are 25 and count "15 years experience" because they started programming at 10. It's just not the same thing, especially when most people only count professional experience (and full time at that). 15 years of programming experience < 10 years full time experience in an enterprise or startup environment.
I'm counting from when I dropped out of college and started working full-time. Maybe only 21 years ago, it's a little hazy now. I'd been writing code for seven or eight years at that point.
It's pretty impressive, then, and nonetheless, I'm just a lot less impressed when somebody says they have 10 years experience and it equates to 2 years of full time, enterprise or startup experience, and 8 years of "I'm going to school full time and program 3 hours a night." I did program and experiment when I was in my teen years too (late 80s, early 90s) and still cringe when people count that as actual experience. Not that I'm constantly learning and growing at my full time job, but meetings, documentation, paperwork, etc are a large part of the job and count more than not having to bother with it.
Middle years if you go into something like management by the time you're 45, I guess. Though I guess you'd have to have planned out that career switch for over 10 years, in that case...
In most companies if you don't fight actively against it, many times also being seen as not wanting a career at all by others, as most of us get pushed into management.