Why are children so happy? It is because children forget evil very easily.
When someone sees things having good thoughts, he purifies himself and receives the Grace of God.
When someone has bad thoughts, judges or deals injustly with others, he blocks the Grace of God from coming and is clobbered by the devil.
Based on Saint Paisios the Athonite
In this photo, two children from Romania in national costumes playing at Easter with semantrons.