A mental model is a simple way to think about the world.

The most useful mental models are broadly applicable—they help identify patterns across different areas of life to create clarity and spark action.

Here's one I can't stop thinking about:

The hidden debts of life.

When you take on a financial debt, you get:

• Short-term benefit (the cash)
• Long-term burden (the repayment with interest)

As it turns out, this general tradeoff—taking a short-term benefit but incurring a long-term burden—can be seen in a variety of contexts beyond the financial.

When you avoid a hard conversation, you're taking on a relationship debt. You get the short-term benefit of the pain avoided, but you incur the long-term burden of the problem that has been brushed under the rug. Time doesn't heal anything when it comes to relationships. Minor issues become major issues over time.

When you skip your workouts or eat processed junk, you're taking on a physical debt. You get the short-term benefit of the pleasure of relaxation and sugar, but you incur the long-term burden of the compounded health impact of these decisions.

When you procrastinate on your important work, you're taking on a professional debt. You get the short-term benefit of the focus avoidance, but you incur the long-term burden of the last minute panic, regret, and missed opportunities.

All of these things are hidden debts of life—they may create some short-term benefit, but they will have to be repaid with interest at a date in the future.

There's no such thing as a free lunch. The bill eventually comes due.

In your finances, as well as your life:

Choose your debts wisely.