Work hard, save money, quit work. Hike. Repeat for thirteen years!
Worked for me several times by choice (and one year not by choice!).
My career has suffered somewhat..but I make a comfortable enough salary as my needs our modest. More importantly, I would not trade the memories and experience I've had for anything! I am your age (next month), and my obligations are now different than even five years ago. Plan on getting married next year, currently cultivating and building up my skill set...but the idea has not changed of making the outdoors the important part of my life.
I am fortunate that my fiance' also loves the outdoors, believes in a modest lifestyle and has dreams similar to mine.
Now there are two of us working hard, saving money and in ~3 yrs we are doing 'something'. I had a good run from 1997 - 2010. Now, I am just in a holding pattern until the next phase. Adrianna and I have decided very quickly that 3-4 wks of vacation is not enough for us and are making plans accordingly so we can achieve that goal.
Guess, as others said, you have to make the choice of how to live your life and go for it. It will take sacrifice, hard work and diligence..but anything in life worth achieving takes that.
(It helps I live in area where even on weekends I can delight in how wonderful the outdoors can be. Hike among the early Spring wildflowers today with Adrianna. Backcountry ski at 11k ft with the buddies tomorrow! Woo!)