For the rest of your life? And where would you stay the rest of the year? All of these things are fine when you're a student, but they're hardly realistic retirement plans.
So one “hack” is as follows: you live like a student in your 20s, then you put that savings into... well, rental properties (my preference) or the default low fee index fund recommendation. Then you just... peace out. Live like a bum and do work exchanges and volunteer things.
I’m only going to bum it for one year, as I still have some ambition left in my spirit, but people can do it indefinitely, and just go part time if they decide to work again.