It would take a long time to list the various elements that make The Curious Incident of the Dog in the Night-Time great popular theatre. It would be a very long list indeed.
But it was the quiet moments that proved this was theatre of the highest order. It takes supreme confidence to allow very little to be happening on a stage, knowing it's necessary to allow this to tell the story to its fullest. Two stood out for me: Christopher and his father standing side-by-side watching the rain for no particular reason; his dad painstakingly slowly removing his son's vomit-stained top after Christopher has had a fit.
Almost nothing was happening and it was riveting.