People talk about life not being black and white, but really full of many shades of grey. But it's even more than that. The sky and the clouds, the grass and falling leaves... Life is many shades of color.
A beginner will see things in black and white because he is literally reading the rule book, trying to memorize it and follow it all at the same time. It takes experience to learn how to handle mistakes and make adjustments. It takes time to acquire finesse.
A budget is a lot like a diet. When you're new to a diet, you carry the book around and won't have a slice of tomato that's not on the list. When you're new to a budget, you estimate this much for utilities, that much for gas, groceries, etc. and a small spending allowance so you won't feel too deprived.
As you spend time on a diet you learn how to bend the rules and add good foods when you're really hungry and just how much bad food you can get away with.
When my new budget came into a conflict between my desire to have more fun and my car's desire to have more gas, fun won. So that was a mistake, but shouldn't be the end of the world. But I'm still working in black and white. It was a much worse mistake to try to go back and "unfun". I need to accept my own responsibilty and consider other people's feelings and mine too. I will make adjustments to eek the money out of groceries. And I'll eat my ramen noodles with humility while I think about this lesson. : )