Living in a semi-rural setting (cows, horses, and large paddocks next to houses, schools, shops, etc.) before developers moved in.
Koalas and wallabies living in the area (nearly all gone now - see above)
Almost everyone in the same area being white and all speaking the same language, and not being from Asia, Africa, or the Middle East
Surfing, before it became popular with "everyone" (foreigners, rich people, clueless wannabes, etc.)
Freedom to be politically incorrect without consequence
Being able to afford to own your own home
Life before social media and smartphones
Commodore 64
Coin operated arcade games at fish and chip shops (there's MAME, but it's not the same)
"Old school" fish and chip shops
80s martial arts movies
70s - 80s australian music
80s wrestling (WWF)
Small corner shops, largely gone due to supermarket duopoly
Actually knowing and talking to neighbours (even just saying "hello")
Unconditional friendships
Being able to enjoy life, instead of constantly thinking and worrying about money
Not comprehensive, but a pretty solid list.