We Moved back to the UK for a better lifestyle, better career, closer to family, more diversity in my life rather than the generic Aussie lifestyle, better build quality of my house, to earn better money, living in a country with old buildings history and architecture and as I've been there seen it and done it, it wasn't for me although my family and I have the life experience if living down under.
The journey down under isn't for everyone and for you going back may be stupid as you are enjoying it ATM in Oz, but for others it's a right decision to move back and experience another adventure.