For the customer who leaves the review content of "Tastes like Australia.", when was his/her first purchase date?
review content of "Tastes like Australia." refers to Review = 'Tastes like Australia.';
SELECT T1.FirstPurchaseDate FROM customers AS T1 INNER JOIN rootbeerreview AS T2 ON T1.CustomerID = T2.CustomerID WHERE T2.Review = 'Tastes like Australia.'