Some retain memories from that age range, but it isn't the norm, sure. I definitely had strong memories from age 5 or 6 that lasted well into my teen years, which surely had an effect (they were mostly bad ones—I used to do some
terrible ruminating at night).
Agree with he overall point that poorer material circumstances in the 0-5 age range likely has little effect, provided it's not to the point that basic things like good nutrition become a problem.
> Certainly on the other hand, it makes some things easier if you don’t have to sweat the cost of a doctor visit, but it’s hardly prerequisite.
Child care and healthcare costs in the US pretty much ensure that anyone with young kids who doesn't have a household income well over $100,000 is gonna feel like they're struggling. There's so-poor-you're-getting-quite-a-bit-of-assistance, which obviously feels like struggling (because it is), and then there's a big window of diminishing assistance in which those two things (especially) tend to eat all your extra income, before you finally hit a point at which it feels possible to keep your head above water without cutting expenses to the bone. It's easy to spend north of $30,000 on those two things per year, if you've got a couple kids and don't have absolute top-tier employer-provided health benefits (very few have that, and they tend to have huge salaries on top of it), and that's without splurging for, say, some super-fancy day care/school. And that's if no-one in your household has any health problems that year! And without costs for diapers, or clothes (very cheap, mostly, just buy used and in bulk), or food, or anything else. The only way to significantly diminish those costs is to have family that can take over most or all of what would otherwise be paid childcare, or to have one parent stay home, which usually only makes (financial) sense if you have lots of kids and the parent staying home had fairly low earning potential.