I live with a tight budget too and I think that a person is solely responsible for failing to achieve his/her goals. For example my wife keeps talking about how many things she wants but she can't get a job. I got a job as an iron worker just to be able to earn something. I waited until the opportunity came and started teaching kids at a professional high school about iron work. It's really about how persistent you are.
As far as credit scores... I don't get those. I have a score in the 650-700 range and I've never missed a payment or anything. My wife is above 750 with no income and no financial history whatsoever. If anyone can explain that... be my guest! I follow everything I read on free sites like creditrepair.org and still I'm barely pushing it up.