The outdoor adventure, the froth and stoke, the head game required, and the ability to go that bit further and get deep into the expanses of the natural world to places few would venture. Climbing is one of the few things that can guarantee you 100% presentness and allow you to reach beautiful flow states while ascending cliffs with your best mates. It's a pretty surreal endeavour at times.
I actually started properly climbing when I moved to the Snowies, learning everything I know within the last 2 years. Living with 2 of the biggest frothers I know (Dyl first and now Haz), has had a big influence on me. I'm now a lead climber and plan to share that stoke for climbing with others, teaching them the ways! But before that, I was messing around in boulder gyms socially.
Physically I find it tough if you're working on the hard stuff, like tough boulder problems or pushing the grades, but as Haz said, a lot of it is mental! To be honest, a good climber understands the movements and their body and doesn't have to be crazy strong. It's a bit of a dance, or yoga on the wall on the big long routes.
As a base, functional strength developed by body weight and weighted compound exercises definitely help, as well as general fitness (running, swimming). Pulling exercises make pulling on rocks more natural. Then comes the specific finger strength, grip strength, endurance training and climbing techniques that the boys know much more about than I.
The mega climbing areas in Australia are the Blue Mountains (NSW) and the Arapiles (VIC).