We just can't let go of some decisions. We replay them in our head and imagine alternate endings.
These sorts of looping mental videos are called counterfactuals. Northwestern University Professor Neal Roese says there's real value to wondering "if only."
"Counterfactual thoughts are generally useful for us in terms of providing a set of options that we might act upon in the future," he says. "This can lead to improvement. It can lead to learning from experience."
But counterfactual thinking isn't always so constructive. Counterfactuals sometimes appear when they're not needed; they can also fail to appear when they would be most useful.
This week, we try to understand why some events prompt these "What if?" questions, while others do not.
We also look at the decisions that may eventually be contenders for counterfactuals—the decisions we have yet to make.
Psychologist Dan Gilbert says that no matter how much time we spend thinking about the future, we don't get any better at predicting it. That's why, as he writes in his book Stumbling on Happiness, divorce lawyers and people who remove tattoos continue to have a steady stream of customers. From Dan, we learn where we go wrong in making our predictions and how we might make our future selves happier.
Hidden Brain is hosted by Shankar Vedantam and produced by Jennifer Schmidt, Parth Shah, Rhaina Cohen, Laura Kwerel and Thomas Lu. Our supervising producer is Tara Boyle. You can also follow us on Twitter @hiddenbrain, and listen for Hidden Brain stories each week on your local public radio station.