When Rich Lister Barry Lambert and his family gave $33.7 million to the University of Sydney to fund research into medicinal cannabis in June 2015, he liked the idea he was helping to break a taboo.

The retired accountant – who sold his business Count Financial to the Commonwealth Bank for more than $373 million and reportedly had never smoked a joint before becoming the plant's most notable (if unlikely) advocate – hoped the record donation would help more people like his four-year-old epileptic granddaughter, Katelyn.