I quit my job in October of 2008 (was 31 at the time) and went backpacking for a year. Best year of my life.
Came back, got rehired at the old job. I don't like it. Currently it is funding one year of massage school and my next trip which will be a one year motorcycle ride down to Argentina and back. Maybe longer...
It is tenuous and risky in that the more I do this, especially at this age, the less easy it becomes to live an everyday life. But as I learned while backpacking I'm not happy unless I'm doing interesting things and taking risks on a regular basis. Once I experienced being "for real happy" there was no putting the genie back in the bottle.