Before we go any further, I should point out that if I had my time over again, I would not waste my time studying books I never understood, or calculus I never used, but studied electric guitar instead. I can't play any instrument but I wish I had started when I was young when my brain was still developing. It's too late now.
In any case, I think that if you are not famous by age 25, you've missed the boat, or at least you have to be outstandingly good or lucky. To borrow a line from Cold Chisel, "the money I saved can't buy my youth again".
Nevertheless, these bands provided a soundtrack to my youth and a lot of enjoyment. I only saw four of them live. If a band has a home page, I've linked to it but most of them disbanded long ago.
What follows are the bands that I liked and I've written a little of my impressions of each. All opinions are entirely my own and you will probably have different ideas.
If your Australian and in your mid-30s, it's time to reminisce. If not, enjoy the ride.
As a general reference, you might be interested to see the Australian MusicWeb Site, "a series of links and pages that exist as a tribute to Australian music."