There are a few reasons for why Australian door knobs are so high. The first reason is that most Australians live in houses with verandas. A higher door knob helps to keep the door shut when there is wind blowing around. The second reason is that many Australians have tall family members or friends, and a higher door knob makes it easier for them to open the door. Finally, since Australia is a hot country, having a higher door knob helps to keep the inside of the house cooler by preventing heat from entering through the bottom of the door.