Sometimes, the hardest thing to do is to follow your own wisdom. At least that's how it is for me. The moment absolutely anyone says something negative about me or my work, I start to doubt myself, even though I know better.

That's bad, and it's unnecessary. There are many times, maybe even most times, when ignoring criticism will make you much more effective than paying attention to it. Here's why refusing to listen to criticism--or maybe blocking it out, so you never hear it in the first place--might actually help you:

1. You're hard-wired to over-value the negative.

Toughness coach and author Jason Selk opened my eyes to this when he explained that the human brain tends to focus on that which upsets and frightens us. That made sense for early humans, who were likelier to survive if they focused on the venomous snakes in the jungle rather than the butterflies. But that negative orientation no longer serves us well. (Here's how we can train ourselves out of it.)

Even though I'm perfectly aware of this phenomenon, when a random tweeter commented that I write about myself too much, I began making my writing more impersonal, without even really thinking about it. More recently, a commenter called one of my columns banal and it bugged me for an entire evening. More than a thousand people thought the column was worth sharing, though. Why did I focus on that single nay-sayer?

Because, even when we're aware of it, our tendency to focus on the negative is tough to overcome. Next time you find you're obsessing because someone said something critical, remember it's not you, it's your inner caveman doing the thinking.

2. It might make you unhappy. And that's not good.

There's ample evidence that the unhappier you are, the worse you perform at work, the worse your health, and the more unlikable you are. And that listening to negativity is actually bad for your brain. Before you let a nay-sayer do that to you, consider very carefully whether it's worth it.

3. Your critic may have questionable motives.

Back when I was single, a friend brought over an available man for dinner one night. When I casually inquired about him the following day, she felt she had to tell me that he'd spent the ride home gushing about a different woman who was at the same dinner. Well, of course she had to. She couldn't have just said, "It turns out he's met someone else," or something equally neutral.

We've all heard those phrases. "I thought you needed to know." "I didn't want to leave you in the dark." "I just have to be honest." Next time you hear them, ask yourself if the person making the comment is truly trying to help you, or if there may be some other reason they just have to tell you the bad news.

4. It might not be coming from someone you respect.

If you receive thoughtful, objective criticism from someone whose judgment you respect, then you should indeed pay attention. But if not, why on earth are you listening to this person? In particular, why are we so quick to take anonymous online comments to heart--when we know there are people out there who believe dinosaurs are a hoax?

5. It may stop your forward momentum.

This is a very, very real danger. I think, for example, of some of my experiences at the American Society of Journalists and Authors, a group composed of freelance writers, who can be hard to please. During more than a decade in leadership, I've seen many good initiatives get stuck in the mud or abandoned because a few people complained, even though they might have benefited the majority of our members. I've seen good ideas abandoned before they were ever tried because of this fear of criticism and complaints. You're much better off plugging your ears.

6. You might start believing it.

This is the biggest danger of all. We know from the new collection of all-time most popular TED Talks that watching the news can be bad for us because it makes the negative seem normal. That if we believe we are good people who are worthy of love, we will indeed be loved. And if we believe ourselves to be strong, we tend to act strong, and thus become strong.

What we believe about ourselves is an incredibly powerful thing. Don't hand that power over to anyone who doesn't deserve it.