My wife and I have a pretty simple method. First, we each have our own bank accounts with our own spending money. Then, we have a joint account that we use for bills. Finally, we have a separate bank that we use for groceries and gas.
With these allocated separately, we can each have our own spending money, and have enough in every other account to take care of what we need. The paycheck just gets split between these in different direct deposit amounts.
The most important thing is to understand your costs, plan them out, and be aware of what comes out and when. Then, you just follow that plan. The biggest part is making sure you know that you can only spend exactly that much on yourself, which is where our individual accounts come in handy. Whatever we want to buy, we can, because we know safely that our needs are taken care of.
Since we have our math to allow more money in than money out, each account (minus our spending ones) accrue their own savings, and can be transferred between at any time. Overall, it works for us.
Humans create an AI computer. They propose the question of how to get more energy. Then, they wonder what will happen once the energy they collect runs out. So they decide to ask the AI, “can entropy be reversed?”
The AI responds “insufficient data for a meaningful answer.”
This repeats for generations. Trillions on trillions of years. And eventually, after everything has left, mankind is no more, and all that remains is the AI in a state of hyperspace, between spatial reality, it finally decides it has enough data. Its response to this collection is to take it upon itself to reverse entropy, and release energy back into the universe.