Walking or riding my bike to school was certainly not an option. I know very few people (no one?) for which those were options. It was difficult to visit my friends as well so I spent a lot of time alone.
I'm in my early 30s, and I walked to and from school fairly often growing up in a suburb. My wife is the same age and living in one of the largest cities in the country used to ride the subway to and from school, but basically had the same experience of being able to do it unsupervised for at least some portion of her school years. It's hard for me to imagine what circumstances would lead you to not know anybody who had that option at all.
It happens all the time in newer suburbs. Schools, particularly elementary schools, are almost always built inside of neighborhoods where all the local kids will be walking to school. Now, there are still buses, probably somewhere between a third and a fourth of the kids live close enough to walk to school. However, those who do are generally expected to walk to school in every city I've lived in.
