In the past two-three years, I lived in Boston, Portland, and San Jose. Boston and San Jose are fairly expensive; Portland is a lot cheaper but it's still decently expensive.
I guess this is fairly impressive. I'm a college kid and I am doing a co-op program; five years of college which include 8 normal semesters and 18 (or in my case 20) months of work. So after two years of normal college, the last years are six months at school and six months at work.
I earn enough from six months of work to pay all of my living expenses (including rent, and some spending money) for the whole year. And tuition for six months. And for my car. In short, 100% independence from my parents. Lots of people manage to do this way earlier than I did (at age 20) but supporting that from only six months' work is not super easy.
I mentioned on an online forum that I eat $30/month (by choice, so I can save the money for more important things). I listed what I buy and a sample list of recipes big enough to rarely repeat dinner for a month. I was quite detailed, though I made sure to say that this worked for me, and may not for other people. I mentioned that even double my spending - making a grocery list that would work for 99% of the population - was still way cheaper than most people live.
I got a lot of disbelief, which is fine, and some choice words. But I also got a lot of thanks, which was nice. But the reason I'm bragging about this is due to the people who took it deeper. Some people asked me for help with their budget, so I would take their zip code and look at the grocery stores in their area and point out food that was just as cheap as I pay, that they had no idea existed. And some people went a step further, by taking my list to the store and seeing if I was lying - and in the end, found that some food was more expensive, some cheaper, and the overall guideline doable. I'm bragging because some people cut their grocery bill in half, and that's awesome.