Well, we used to have horses...

There's a reason all the old buildings in big cities are elevated a few steps above street level...

You could probably get a similar reaction if fossil fuel sales were given in the equivalent of trees or fuel crops. Someone might question running to the store just for donuts if they imagined burning half of a tree or 40 pounds of grain or something in the process, rather than just a bit of gasoline.

Yep ... that's about two chocolate bars every kilometer ... and that has not really changed too much with newer motor generations as it is mostly a function of how much gas is used.

You can easily walk tens of kilometers in a day. 10 km us basically nothing, 20 km would be somewhat taxing if you are unprepared ... But some (crazy) people are doing 100 km walks for "fun".