Among other things, chapter 9, Finances, of Extreme Agility, by Michael Küsters, brings attention to one of my pet peeves: sunk cost.
"Once you are aware that what you do is not the most valuable thing, stop it. Don’t continue. The effort, time and money spent to this point is lost. But it’s still cheaper than losing even more effort, time and money that you still could invest for more valuable things!"
What about you?
Are you usually able to stop wasting effort, time and money before it's too late?
