Behavior
Sunk Cost
Money already spent that shouldn't drive the next choice.
In plain language
What you've already paid is gone regardless of what you do next. The only useful question is what the next dollar should do.
Why it matters
It keeps people paying for things they stopped wanting years ago.
Put it to work
Own more. Owe less.
Every word here shows up in a real decision. Run your own number, or get the next one in The Letter.