It's easy to get into that kind of mentality. I know when I had a car, I really couldn't gage distances or figure out what I can handle physically. I don't think many people do. When I was trying to find a house in this city, I was considering a place maybe 8 to 10km away from my place of work. I didn't have a car or a bike back then, so I had to consider options like public transit. My dad put it in perspective for me. That distance is possibly a few big city blocks... and I would walk that distance all the time when I lived downtown. It just seems further away because there's nothing interesting to look at when you commute that way through suburbs.
I finally settled on a house that was about a 1/2 hour walk away, 10 minutes by bike. Some car-bound people still think that's too far. People literally cry if they have to walk more than 10 minutes anywhere. People think that taking 1/2 an hour to go up the block because of traffic and finding parking is acceptable, but walking there? Oh no, don't be a plebe! It's all a matter of perspective.