I have never been in a position to just up and quit a job without having something else lined up. Are you all trust fund kids?
First time I took a year off to ski bum and travel (late 2008 just as the recession started to get rolling) In 2012 I took nearly a year off to start my own thing.
I noticed both times that as soon as I didn't have any income, I knew where every dollar I spent went and lived very frugally to stretch my funds.
In general, I live way below my means and save as much as possible. I'm early 30s and have always had shared living situations (either SOs or roommates) and that means right now my living expenses are about ~12% of my take home pay, so basically that means even after I max out my 401k I have a few thousands of dollars per month to do what I want with.