When I was young, there was an older boy in the neighborhood that every one called Bubber. The story, or what I understood to be the story, was that he had, as a small child, been hit by a city bus and had been mentally impaired by the accident. His family had received a settlement from the bus company, part of which was, I believe, a bus pass. You would see him everywhere on the North Side buses. Some times he would have boxes of cards that he would sell, sometimes seeds. Sometimes he would show up at the park and play the simpler games with the other children, usually younger ones. He was a real good guy. He was speech impaired, causing a slight stuttering and slurring when he talked (the nickname), but he could make sense, and had an infectious laugh when things were funny.
Sometimes a mean older boy would taunt him or pick a fight. We were too young to do anything, but even then we knew which of the two was really retarded.