Modern children are different. For example, in the low income community that I live in statistics show that 60% of babies are born addicted to drugs. This is of course going to affect brain development. Families are broken and unstable, neighborhoods are chaotic, drug and alcohol use are rampant, kids go to bed hungry because mom is either too busy with drugs or with her newest revolving door boyfriend to bother to properly look after her children so malnutrition becomes a problem, etc, etc.Things like stress can affect brain development in kids and these kids have incredibly stressful, unstable lives.
My dad is around your age and he also grew up dirt poor but he had a stable, loving two parent home of good sober hardworking Christian folk. Times were lean but they always managed to scrape together enough food so nobody went to bed too hungry. These type of families are virtually nonexistent in today's world.