As for the cause for the celebration it is impossible to avoid the conclusion that being a member of the royal family must be a most dispiriting experience and a clear abuse of their human right to a happy and productive life. Living a charade and surrounded by toadies must be soul destroying. It is quite understandable why Harry opted out.

So sympathy for the Queen and thanks for providing a model of moral virtue and duty allied to an ordinariness - she is just like everybody's grandma albeit more expensively dressed -  that we can all identify with and, hopefully, try to imitate.
Her only error was to ignore her grandmaternal instincts and give in to Tony Blair's entreaties to return to London from Balmoral at the time of the national hysteria over Diana's death.