A good friend's mom just died. Out of nowhere, he told me that his mom never liked me very much. Frankly, the feeling was mutual, but I of course never said anything. While I don't want to start a fight or anything, I'm bothered that he told me this. How should I let him know?

--Irritated

When somebody talks trash about you, it's natural to want to respond. Unfortunately, sending this woman a "we need to talk" text will require a mediator with a Ouija board.

It does seem pretty rotten that your friend suddenly let his mom's opinions of you off-leash. However, consider that keeping a secret -- having information of interest to another person that you need to keep barricaded in a closet in your head -- is mentally and even physically stressful. Research increasingly finds that the body and mind are co-workers. (Action leads to emotion and emotion to action.) In secret-keeping, holding back information causes psychological tension, which brings on physical tension -- which can make keeping the secret both figuratively and literally a pain in the neck.

Research on secrecy by psychologist Michael Slepian suggests that it isn't concealing information but having a goal of concealing information that stresses us out. Unlike many other goals -- the kind you can complete and check off on your to-do list -- the goal to keep a secret has no endpoint. This turns keeping a secret into a sort of zombie goal, a goal that won't die -- or, in researcher terms, "an outstanding intention." This makes it more accessible in memory -- to the point where the mind tends to wander to it. And this mental reflux has some psychological costs: "The frequency of mind-wandering to secrets predicts lower well-being," explains the Slepian team. "Thus, what seems to be harmful about secrecy is not having to conceal a secret but having to live with it and having it return to one's thoughts."

Other research, exploring willpower, finds that stress and "aversive" (feelbad) emotions like sadness diminish our ability for self-control. So, your friend, under the emotional stress of grieving his mom, maybe lacked the energy he normally had to keep his mom's feelings stowed in the, uh, overhead compartment. Obviously, you'd prefer to unknow this info. However, if this guy generally isn't unkind or insensitive, you might want to let this go -- especially considering the advantage you have over a lady who's now living on somebody's mantel: "I will come find you and reduce you to ash! Oh. Wait."

For pages and pages of "science-help" from me, buy my latest book, "Unf*ckology: A Field Guide to Living with Guts and Confidence." It lays out the PROCESS of transforming to live w/confidence.