I doubt I’m the only one who grew up hearing, “Make sure you make a good first impression.” At the time, I probably wondered whether that was my parents just being persnickety.

It turns out they were right. This realization occurred when I reconsidered my take on a person I had historically viewed as a bad combination of nerdy, narcissistic and dull. The only other attribute I didn’t add —because, even then, I knew it wasn’t true — was “mean.”

But then, as luck would have it, we were seated at dinner together. Suddenly, I found him a good listener, full of helpful information on topics that mattered, and appreciative of what others had to say.

Could this be the same person? Absolutely. So, what happened? The short answer is that he didn’t match my first impression. It turns out that first impressions are very lasting and remain beyond their expiration date. There are various estimates of the accuracy of our first impressions, but the magazine Psychology Today estimates first impressions to be only 30% accurate. Other sources, like Nobel-prize-winning psychologist Daniel Kahneman, believe it is much higher and that our first impression “sets up our subsequent beliefs.”

Even if Kahneman is right about the accuracy, he cites two biases that cast some doubt on first impressions. Namely, there is confirmation bias, where we favor information that supports our preferences and disregard the rest. There is also the “halo effect,” where we take our positive impression of someone, which can be tied to something very specific, and expand it as their whole. This latter phenomenon helps explain “Lookism,” whereby attractive people receive untold preferences, such as assuming they’re smart.

Interesting factoid: 43% of U.S. presidents have been 6 feet or taller, and all modern presidents (since Kennedy) have been at least 5-11-and-a-half. Compare that to the population in general, where only 15% of people are over 6 feet. Do we have a bias that contributes to an initial impression that height equals power?

The problem with first impressions is not just that they are sometimes wrong or likely have biases, as Kahneman points out, but they are also so hard to shake. One Harvard study revealed that it takes eight subsequent positive encounters to reverse a negative impression. This also means perseverance is needed by the person trying to correct an uncharitable perception.

This made me consider my experience with first impressions. Countless people started strong, only to wither in my mind. Regarding public figures, I loved Bill Clinton until I didn’t. Same for Bill Cosby. Within my circle, some friends turned out to be not as sterling as initially thought, but others came through and offered a happy surprise.

In truth, especially in the public sphere, it was far harder to come up with examples where I held someone in low regard only to have a reshaped positive opinion. When I asked others to name an example, they had a similar difficulty.

I knew the pickings were slim when the first example that came to my mind was George Wallace. For most of his life, Wallace was a segregationist and unapologetic racist. Late in his life, he considered his views a huge mistake, for which he apologized and sought forgiveness. He remarked: “In a way that was impossible, I think I can understand something of the pain Black people have come to endure. I know I contributed to that pain, and I can only ask your forgiveness.”

Ronald Reagan was the other example of a politician whose initial perception went from negative to positive. I initially considered Reagan to be a dumb actor and a stereotypical unfeeling Republican, but I later came to see him as intuitive, warm and thoughtful. He profoundly shaped history with his famous plea, “Mr. Gorbachev, tear down this wall!” And the Berlin Wall fell.

This is all to say that while first impressions are real and lasting, it is worth the effort to reconsider our take. After all, people change — we do, they do — and growth can happen.

If Will Rogers was right that “you never get a second chance to make a first impression,” maybe we should place the burden on ourselves to reconsider our perceptions. We just might be wrong.