I think what personal finances really come down to is your approach toward money. Meaning some people have no idea where their money is being spent, which is why David Ramsey is popular with some people (personally I never heard of David Ramsey until a couple months ago). He offers a very simple, common sense approach to making a budget and spending only cash to ensure you know how ever dollar is spent. This can help some people develop a solid understanding of where their cash is actually going. For others, he is far too basic as they have moved well beyond his baby step system.
I've always had a budget, and that didn't change when I got married. Budgets are useful in two ways. If you are having problems with money, a budget can help provide insight to where your money is going. These people need to reference their budget on a daily basis to ensure each and every dollar is in line with their plan. Otherwise things can spiral out of control fast. For others, a budget is simply a good sanity check that should be referenced every 1-2 months to ensure their spending matches their plan. These people have developed the financial discipline and long-term financial look to basically be on autopilot.
To help spur further discussion, here is my family's (1 wife, 2 young kids) budget. I’ll use percentages of gross income to help make it transferable to others.
Investments: 30%
Rent: 18%
Taxes: 13% (Federal, FICA, SS, Medicare; no state taxes)
Leisure: 6% (restaurants, baby sitter, movies, etc)
Groceries: 5% (I am shocked at how much food costs!)
Autos: 4% (own both cars outright, this is gas & maintenance fund)
Charity: 4%
Utilities: 4%
Kids stuff: 4% (clothes, toys, books, shoes, sports, etc)
Vacation fund: 3%
Medical/Dental/Life & Home & Auto Insurance: 3%
Pre-school: 2%
Christmas gift fund: 1%
Cell phones: 1%
Misc: 2%