I'm 39, my husband is 41. We bought our first house when we were married 15 years ago, and we moved up to a larger house four years ago. It took us 13 years to live in a paid-for house. We made an extra payment each and every month, with the goal of living mortgage-free.
We both have professional degrees and decent jobs. Still, we don't make a ton of money -- I suspect that many other people on this board make considerably more -- but we've always lived BELOW our means. We started out dirt-poor, and we just refused to become accustomed to luxuries while we were still in debt. Both of us worked our way through college (neither finished in four years), and we both refused to take out student loans. We live in a less expensive house than most of our co-workers, we drive used cars, and we don't buy lots of "stuff". We don't eat out on a regular basis, we don't go to the movies, etc. We've never been divorced, and our only two children were born within this marriage -- I don't mean that to sound judgemental towards others, but child support, maintaining two houses, etc. are a serious budget killers -- we don't have them. The fact that we live in an inexpensive area of the country helps too.