What am I, as a self-employed, middle-aged, male with several generations of Celtic forebears supposed to celebrate in 1988?

Nothing about 1788 itself appeals, since unlike the US American Bicentennial, we are being asked to excite ourselves over something done to this continent and its occupants by the British Empire. In 1976, the US Americans could celebrate something they had done to the British. Hence, 1988 is not such a special date for European Australians.