The opening ceremoney illustrated some historic events that affected the British lives the most. The events themselves might not be all hope and glory, but all of them led to a profound change in Britain, in some cases the world.
About NHS, you've got know the history of its creation to fully appreciate its significance in modern Britain, esp in today - the era of austerity. It is rather a Mr. Boyle's political statement I suspect.
THis ceremoney is very "British". THe world out side may not be able to understand all the references.