Considering your age, a lot of the food you ate for decades was very different from a good part of the ‘food’ served today. Your beef was likely grass fed for quite some time, your milk was mostly milk with limited/no hormones, the sugar was cane sugar not high-fructose corn syrup, your chicken was all chicken and limited meds/chems, goodness, even your chocolate bars had real cacao and cocoa butter (as opposed to ‘chocolatey’ and ‘vegetable oil chocolate candy’ today).
So, you ate well and hearty, and you’re still around and doing well. However, your personal experience largely stems from a time when food was ‘real’. You did not build a dietary foundation of cr@p, and Id even bet the coca cola you drank in your youth was likely more healthy than vitamin water today (slight exaggeration, but not by much).
This is a thoughtful well reasoned response.
I have a healthy diet and have for years. Very occasionally I will try a food from my childhood. Not good.
Heck until I was 21 ice cream had to consist of cream.