Australians are used to change their own tyres?

Let's imagine that you are driving and notice that you have a flat tyre. Do you have an extra tyre in the car? Do you have the tools to change it and know how to do? It caught my attention reading a handbook about traffic rules in Vic , it states that when you have a flat tyre, recommendation is not to change yourself but wait for road assistance. But I know in other countries usually people has an extra tyre to replace when needed. I was wondering what is the use here.