Things like that do stay in the mind, Alie and upset you for a long time afterwards. Sometimes it is what more you might have done.
Several years ago, I was in the supermarket on a pretty cold autumn day. I could hear a child grizzling, and when I came round into the next aisle, a couple zipped up in anoraks were pushing a trolley in which was a boy of about 2 or 3 in just a Tshirt who was doing that low-level miserable crying of a child who had got stuck in grizzling mode.
I stopped to speak to the child and take his mind off it a bit (sometimes a different person talking to them is interesting enough to change the record) and said something like "Hello, there. Is that bad then?" and the mother said "He wouldn't eat his breakfast!" as though that were a crime, so the scenario was that there was a set-to over breakfast and he got stroppy and had been carted off to the supermarket as he was. I moved on to get my shopping, and it was only as I was leaving that I saw that he was still whinging as he was put into the car - he must have been half-frozen and had an awful cough - and I felt so guilty at not pointing out that a sick child often does not want to eat and is cranky. They did not seem to be very good at parenting.
A while later, a case of child cruelty came up - not in my town - where the parents had punished a child by feeding him lots of salt, which made him ill, and not keeping him warm enough - and the photos looked very like the little boy! They had adopted him and had no idea how to discipline a small child. I had nightmares that they might have been on holiday here, and I had missed a chance to intervene (interfere?)