I would get a heckin' mountain of smashed avo, that's for sure.
Okay but honestly
I would bank most of it. immediately send at least 10 mill to charities anonymously, and not tell anyone. I would pay off my parent's house debt and buy my own little apartment somewhere. And THEN I wouldn't get HECS/HELP debt, yeh boi
To be honest I would not find it hard to save it - I'm sort of a money squirrel, so thrifty is the name of the game. I would keep going in life as per normal - get a job somewhere, maybe go hiking more often and get myself a pretty Indian Scout and maybe a good car but I would keep the money banked and spend the interest (by which a person can still live with, like, 200,000/annually). Write a will giving some to cancer research, some to family, some to World Vision, some to other causes. All in all, I wouldn't end up really using it for much during my life, but I'd live pretty affluently off of the interest dregs. Is it weird for someone my age to plan for things after death?