Since I'd venture to guess I spend more time in grocery stores than anyone else on the board, I could share a few things about stores that I have modeled as an archetype of the general public.
The most prominent point being: as soon as people walk through the doors to shop, they literally leave their brains in their vehicle. I'm no different. I see people do things that make you go "wtf were are you thinking?" and then when I shop I noticed myself drifting towards those patterns of behavior and catch myself and ream myself out!