Only this much.

If you had only 24 hours in Paris, how would you spend your time?

Which places would you be eager to go to? Which ones would it become easier to say no to?

The constraint, here, helps you make better choices. You ignore the good to haves and focus on the must haves.

How would your decisions change if you do this with your time and money?

Because every day, we all get only that many hours. And looking at money from this perspective helps us make choices that make us happy.

You only need a pen and paper to get started.

And if you'd like to explore more, Cal Newport's Time Blocking Planner is excellent at doing this with time. And YNAB.com is a tool that helps doing this with money.