While reading the latest MMM post about saving in your 20s, I kept shouting in my head, "OH YES, YES, THAT'S WHAT I DID!"
I turned 30 about 9 months ago, but I lived my twenties way below my possible "standard of living" (which is really just code for "spending"). I didn't really have retirement in mind when I started working and saving, this just seemed a natural and intelligent thing to do with my money. So I have a fair amount of savings now, but I was too reluctant to invest it, so it hasn't grown as much as it could have. Still, I'm not beating myself up about it too much, since I know I have much more savings than the average thirty year old.
Right now, my housing expenses (including heat!) are at about 20% of my income. I save 50%, and the other 30% goes to food, home supplies, public transit, gym membership, and a bunch of non-essentials. My goal for October is to push my limits until I can save 60%. If I can consistently pull that off, I think 70% will seem more achievable to me, although I still think it's going to be painful. I'm a big city apartment dweller, so I can't grow my own food or build a home gym to cut costs. But I'll consider it a challenge to see how close I can get.