Lex - Mindset is all important. Those couples that had children early were not professionals at the time. They didn't have high powered degrees and everyone thought they were crazy when they got married and had kids. These people live in the same neighborhoods as those professionals that have how powered degrees. The only difference financially is that those families that got started earlier have far less debt.
I am reminded of this post and myself:
http://www.sosuave.net/forum/showthread.php?t=172322
During high school I developed a skill and I honed that skill during summers. When I graduated it was decided that I go to college and pursue a career unrelated to that skill. And thereby begin the process of accumulating debt. After 10 years of pursuing that career, making lots of money along with extremely high levels of stress. I was on high blood pressure meds and 50lbs overweight by the age 34.
A job came up that would allow me to use those skills I learned back in high school. I took a pay cut when I decided to make this change but my health and general love of life is far better. Now I am making as much money doing this as I did with my other career. I am doing very well with this new career and I'm even beating others with 20-30 experience in the field.
I often wonder if I had used my skill right after high school where I'd be.
After college I decided real early on that I wouldn't borrow any more money. This has helped me where it has hurt many of my peers. I pay for everything with cash, I have one credit card but I do have a home mortgage.