Even for those who don’t build their identity around their job, a lot of folks are just used to having something to do.
I work in retail, and I’ve had a surprising number of old folks ask if we have any part time jobs available - they’re not looking for steady paycheck, they’re looking for something to do two or three days a week. Even if your job isn’t necessarily who you are, it’s still a reason to get out of the house.
Their math was flawed, but I’m not really sure how to explain the math part better. I get what they were going for, though.
It’s closer to decimal divisions of an inch, so a .223 caliber bullet would be a hair shy of a quarter of an inch (.25) wide.
Edit: just realized you had the second part of that already