People don't carry around 35kg of groceries each time they go to the local supermarket. They buy a tiny bit of what they need each day, walking back from home/school, since it takes so little time and often it's on the way, anyway.
Carrying 2-5-6-7-8-10kg is quite easy.
They literally will not believe that it is possible to but a days worth of groceries every day, and get fresh, quality food.
But the more people saying that it can be done, and is a superior way to shop, the more likely we will convince them finally.
With the return trip time + parking, you can see how it's much more sensible to plan your shopping ahead of time to optimize for the fewest amount of trips possible.
Even if you currently live in a borderline walkable area, there's a solid chance you grew up in an area where driving to the store was a norm and thus contributes to the decision to walk vs drive.
However, even when patiently explaining this difference, it is a mental leap too far to consider any change. Not only is it the physical design of the stores and car-only infrastructure, a lot of it has to do with package sizing and pricing structure, as another poster pointed out; smaller quantities get massive markups in US stores, for no good reason other than once they've got you in a store, you're fairly captive and they want to extract the maximum amount of money from you so that you don't end up elsewhere.
Until people experience it, and realize that having a five person family is no challenge at all for this style of life, it's hard to give them the picture.
As I mentioned in another comment, I had the opportunity to live for a year in a very walkable neighborhood, with an excellent grocery store. It was convenient, it was small, the food was high quality, checkout was lightning fast. I found myself going there nearly every day and it was wonderful.
But once I needed to move back to a more car-centered city, the idea of doing this became once again unthinkable. Far too big of a chore to do daily.
Previously, the idea of going to the grocery store every day had sounded like terrible tedium -- but I found myself doing it and it was wonderful.
There's so much of a bubble here sometimes. Narrow minded...dude, not everyone is a single, childless, wealthy knowledge worker that can waste their time to do this.
For the majority of (urban) people it’s definitely manageable. More than 50% of all households in central Berlin own no car, numbers rising.
I used to own a car, and the tipping point from “I can’t do that” to “no problem to do that” was selling the car. It’s an acquired habit for most of us. I now own an umbrella and a good waterproof jacket instead.
You don't just go to buy STRICTLY what you need today. You buy something like 10% over each time. Within several weeks of shopping you'll have a full fridge, heck, even a full pantry.
Then you only need to top up when you go each day. And I'm being generous, you can go every 2-3 days, even.
There are comfortable solution, you need two things:
1. An environment that helps (most European cities).
2. A bit of planning/flexibility/smarts.
If you don't have 1. you're dead in the water, from the start. If you don't have 2., well... get them :-)
