Amazing experience seeing them in the wild. When I was posted to RAAF Williamstown (near Newcastle NSW) in the mid 90's you would regularly see them even on the Airforce base which kept a detailed register of all Koala's on the base and if they had babies.
I was living on the base at the time and had a male park itself in the tree just a couple of metres from my window .. he bellowed for 2 hours. I had had enough and opened the window and told him he hadn't scored a female in 2 hours and suggested he try another tree. He stopped .. looked at me ... climbed down and wandered off to another tree where upon I could hear him in the distance continuing his mating call.
If you have never heard a male Koala bellow .. this it what it sounds like.
https://youtu.be/ocIR6B-YtYE
So .. savour the experience. Sadly I think it will be a rare experience in the future as human urbanisation kills off their habitat.
And for a bit of a laugh
https://youtu.be/-by5gew8OHM