Wait until you learn that some of the sunscreens sold (can't say specifically in Australia, but I know this is the case in the US) only block UVB, so you won't get a sunburn but you will still get exposed to unhealthy amounts of UVA. Basically sunscreen is often optimized to not make you burn, which burning might actually be a good thing since it's preventing you from getting exposed to even more UVA.

Took a quick look and apparently the issue is pretty widespread: https://www.ewg.org/sunscreen/report/whats-wrong-with-high-s...

I use sunscreen myself sometimes but using artificial methods gives me pause. Whenever possible I just wear a UV shirt and a hat instead.

I hope by "UV shirt" you mean practically any shirt and not a specialized product.