YMBAAI:
At a high school camping trip, aged 12, you didn't play sports or gossip with the other kids, but instead you stood in front of a vending machine for three hours, constantly placing in a 20c coin and refunding it, utterly determined to get one that is dated 1966 (the year that the current, decimal, currency was first introduced in Australia).
I didn't find one.
But I got a 1966 20c by accident the very next day as change at a kiosk. 