Several of Sydney's esteemed learning institutions host public lectures a diverse range of topics year round. If you need a break from the silly season, why not attend and expand your horizons. Many of the lectures are free and welcome those wishing to learn new things.
For all of the history buffs out there, the History Council of NSW and the City of Sydney regularly host public lectures given by leading Australian historians. The talks are held at Customs House, 31 Alfred Street, Circular Quay and bookings are essential. The talks are free for members of the City of Sydney library and $10.00 for non-members. Incidentally membership of the library is free for those who reside in the municipality and $15.00 if you don't. Check the website for details.
The University of Sydney also hosts dozens of public talks across a range of disciplines. These range from talks given in conjunction with Sydney Museums based in geography and history to free evening lectures on key thinkers who have shaped society's institutions and beliefs. These talks are given by University of Sydney academics who impart their wisdom in the form of a 45 minute talk on an exceptional thinker from their discipline.
Finally, one of the best places to seek out talks and lectures on the web is found at Sydney Talks. Sydney Talks touts itself as an independent guide which tells you where to find the most interesting public talks and debates in Sydney. It features events across a number of topics, including politics, science, history and the Arts and is a fantastic resource.