someone programming every day for 8 hours a day for 40 years would surely have a greater mastery than someone who only does it part-time. I think you hit it th

someone programming every day for 8 hours a day for 40 years would surely have a greater mastery than someone who only does it part-time. I think you hit it there. We're not disagreeing. I'd just add to your point that one might still retain that mastery gained over 40 years of practice if one dialed things back for the next five years to focus on something else.