I agree that everyone is different so what works for one person won't necessarily work for another. For instance, I usually wear Havaianas flip flops and am comfortable even after 9+ straight commando park days. No pain, no blisters. And no dealing with soaked socks if it rains. (Flip flops are also the only flat shoes I've ever found that don't hurt my shins - otherwise, I'm much more comfortable at least 2"+ heels.) If my mom did that, her feet would be a mess after the first couple hours of the trip. I can't wear any type of tennis shoes, bc the heels rub my Achilles and cause bloody, open sores within minutes. (I have trouble with any shoe with a solid back that comes up over my Achilles (slingbacks are generally fine.)
I'm also sensitive to some types of adhesive. I've gotten to know what works through trial and error; for whatever reason, fabric BandAid brand bandaids don't irritate my skin, but the plastic BandAid brand make my skin break down (open sores). I wouldn't think they same company would use different adhesive, but I can't explain it otherwise.