What an interesting thread. I grew up in the 70s in Europe and I was going to the bakery (10min walk) on Saturday mornings alone at age 4. I was left alone at home for several hours once I knew how to operate a phone (age 4 as well). I was roaming the neighbourhood with friends at age 3. I was taking trains including transfers at age 6 once I could read. I never felt afraid or unsafe.
My mother kept always telling us how I was her responsible child, while my little brother was always in dreamland and would not have been able some of these scenarios before age 8-10.
Now I live on a different continent several decades later and have a child of my own and people are reacting surprised because I let him roam more freely than others would. For instance, he (1.5years old) stays in the children's room of the library (which has doors he cannot open and the librarians know him) for 10min or so, while I check out some adult books on a different floor.
Some people even mentioned that this is illegal and he is way to young to be left alone. I cannot imagine not leaving my child alone for an afternoon at age 6.
I feel most people would think I am insane, but I loved my freedom as a child, I enjoyed unsupervised time and we all knew we had to watch out for one another, those free days were important to me. Our school district even encouraged parents to let children walk alone (without parents) to school, to allow for bonding among the children.
I am having a hard time reconciling my childhood experiences with modern behavior and norms on a different continent.