If you’re 40 and have been lifting for 10 months you probably literally don’t know how hard you can push yourself
I've done a 10-day water fast and the ice baths I do are far more difficult. You come across as someone who has never done an ice bath in your life because you chose to ignore that detail and instead focus only on an irrelevant detail (that I've been lifting for 10 months).
My mental toughness claim rests on my ice bath statement. I also video-record them and take pics of submerged thermometers and use timers so I don't cheat the duration or intensity data on my ice bath logbook. I never said that lifting for 10 months is the justification for my mental toughness.
Why worry about minutiae like optimal weekly set range for hypertrophy or your mesolimbic neurotransmitters when you’re a novice lifter? You aren’t eating in a calorie range for optimal hypertrophy no matter what set range you are at. By your own report what you’re doing is working so just keep it simple. Don’t go looking for problems you don’t have.
I agree with this part of your statement, though.