DS is 4.9, and I fear I may have just tipped him over the edge!
Basically, at pre-school, all the feedback I get is what a lovely, kind, helpful child he is, if not a little bit hyper. However, the second I fetch him, all I get is relentless moaning and whining. I don't know why he's only like this with us, but after 5 mins non stop whingeing and fake crying today (about not going the way home he wanted, not going for some tea and cake, not having Buttons at home, not having my wallet with me) I just snapped!
When we got home, I sat him down and explained to him that he is LUCKY. I told him about all the children in the world who don't have food, water, clothes, a roof over their head, the chance to go to school.
But this is where I think I went too far... I told him that he was lucky, as some children don't have mummies or daddies anymore, and he was HYSTERICAL.
He was literally sobbing and snotting and clinging onto me for dear life
and when I managed to get out of him why he was so upset, he spluttered that he was very sad for all the little children whose mummies and daddies were dead! 
I tried to comfort him as best I could, and told him that being sad for others made him a kind little boy, and he seems okay now, but WIBU to bring up what are probably quite adult ideas about a not-so-nice world? My heart breaks thinking of how upset he was, and I'm worried I've mentally scarred him for life!