Why is it important to let yourself be wrong?

(tw: drunk driving accident)

Being willing and able to admit you're wrong, and more importantly, to use that information to change something about yourself or your life is necessary for survival.  Here's a very simplistic (and not very realistic) demonstration of this fact:

Grogelda is out in the bush hunting for berries for her mate.  She notices a cloud of dust ahead, and it looks like clouds of dust she's seen antelopes kick up in the past.   She thinks nothing of it because antelopes have never been a threat to her before, so in her mind there is no danger.  She goes back to getting those luscious poogleberries of which her mate is so very fond.  The cloud gets closer but she's dismissed it as unimportant, and doesn't even notice it.  Nogelda runs up to Grogelda and tells her she needs to run, that the antelopes are stampeding right at her.  Grogelda looks at Nogelda as if she's a loopy-bat and keeps picking berries.  Nogelda tries a couple of times to get Grogelda to see the danger she's in, but eventually gives up because she has to get to safety herself.  So she leaves Grogelda there.  A few moments later, Grogelda thinks, as she's being stampeded to death, "But antelopes have never harmed me before!"

Grogelda just couldn't accept the idea that antelopes, which normally were peaceful and non-meat-eating could ever be a threat, and she paid for her inability to be wrong, and act on that wrongness, with her life.  By the way, I'm not going to go into all the reasons why this scenario is flawed, so please don't pick on those points, but try to see the lesson I'm straining to convey

Being able and willing to accept that you're wrong, and then acting on that new information, is vital for human survival, all the time and across most situations, not just when antelope herds are stampeding.  Afterall, if Grogelda had just said to Nogelda "Oh, hmm, you're right, those antelopes are running towards me at great speed." then continued picking poogleberries instead of moving out of the way, she'd still be just as dead.

Sometimes being able and willing to admit you're wrong doesn't have an immediate impact for you, but it will have for someone near you.  Possibly even someone you don't know, but whose life you will change just the same.  When you make the effort to be as well-informed about things as you are able to be, you tend to make better choices for yourself and your situation, and by extension, the people around you.

So here's a more modern example that too many people will find resonates with them:

Doris is out with her friends having a nice time at a club.  She believes firmly that eating a lot of bread before you drink means you won't get as drunk.  So she had a lot of bread before she went out, and has been drinking red wine exclusively (because everyone knows you can't get drunk on wine).  So when she decides to call it a night, she's not hammered. She's "buzzed".  Being buzzed isn't the same as being drunk, and so of course she's fine driving herself home, or so her friends think.  Doris has driven home buzzed dozens of times and never had any problem before.

On the way home her sluggish response time and slightly bleary vision means she fails to hit the brakes in time to avoid rear-ending a car that has stalled out in an intersection.  That car was slammed forward into a concrete divider that it was, unfortunately, pointing towards as the driver had been starting to turn left when his car stalled out.  The driver of the car, who wasn't wearing a seat belt because he'd had a cousin trapped in a car under water because her seat belt malfunctioned back in the 1970s, was thrown through the windshield, and only manage to avoid being a quadriplegic for the rest of his life by virtue of having his head smashed to bits on the concrete divider, and so he died instantly.

This scenario is full of points during which the outcome could have been completely changed, or altered just enough that it wouldn't have turned out to be quite so tragic as it was.  I'll just list some of the more significant ones.

1. Doris could have taken her responsibility as a drinker more seriously and learned the facts before she drank.  For instance: that bread does not keep you from getting drunk, and that it is, in fact, possible to get drunk on red wine only.  She also could also have learned that even one glass of wine can impair her reaction time enough to make an accident more likely than it otherwise would be.  If she was in full possession of either of these facts it could have changed the choices she made.  Maybe she wouldn't have had so much to drink, or she might have called a cab, or she might have asked her friends to appoint a designated driver.  Any one of these choices could have changed the outcome, and those are just things Doris, herself, could have done.
2. Any one of the group of Doris's friends could have chosen to be the designated driver, and taken people's keys away, and made sure they all got home safe.
3. The driver in the other car could have learned more about seat belt technology, and the real risks associated with not wearing seat belts (versus anecdotal information about rare occurrences).  If he'd accepted those facts, instead of choosing a course of action based on out-dated information and improbable situations, he might have been wearing his seat belt, and suffered only minor injuries, instead of dying.

 The point here is that you never know exactly when your failure to challenge your assumptions and beliefs could have tragic, or even just unpleasant, consequences.  When you make choices based on reality and facts instead of unsupported or unwarranted assumptions, you have a far better chance of avoiding such situations.

That is why it is important to let yourself be wrong, and act on that by changing how you behave based on the new knowledge you gain.