Cos its only three years after some dumb yanks chucked a whole shipload of perfectly good tea products into the bloody bay! You were a real ‘wild bunch’ back then hey? “Right, to start this reevolooshun I’m going to get rid of all the tea in them these colonies!!!” Not have a riot or a full on coup detate, NEVER!!!
I realise that your independence means alot to you, as it should, but when you come from a country with thousands (thats, like, y’know, with three 0’s I reckon...) of years of history, a little date in someone elses calender means spit. Your is one country among many that had to fight for independence from Great Britain, so I’m sure our Queen just tunes the locals out when travelling to a former dominion.