Retirement is the withdrawal from active working life, i.e. having a job. It is not a US concept.

Right, and a nice thing about software is that retirement doesn’t mean you have to stop doing what you used to do.

I’m retired (I know, I’m very lucky), and I’ve done as much or more coding since retirement than I did in my job. But to be fair, AI has really changed how I’m going about things, and I’m not sure what the future is going to bring. I really worry about my adult children and their careers.

But that's the point, ain't it? If you voluntarily abandon doing things you are basically declaring "I'm dead, ignore that I'm still breathing".