You can't identify a hero from the outside. You might not suspect that Jon Meis, the Seattle Pacific University student who has been described as private and gentle, would tackle and subdue a gunman Thursday, inspiring others to help hold down the attacker until police arrived. Would those other students have acted if Meis had not?

Also yesterday, a man in Pennsylvania ran from his house in pajamas and flip-flops, and pulled an unconscious woman from a car in flames. Why did he do this? He could have called 911. He could have knocked on a neighbor's door and debated what to do. But he simply acted. Why?

And a man in Minnesota jumped 30 feet from a cliff into the St. Croix River to save a drowning 11-year-old boy.

All of these situations, which happened within days of each other, required immediate action. For a life to be saved, there was no time to wait for rescuers. So these people stepped up, at the risk of their own lives, for people they did not know.

When questioned, recurring themes run through the answers of heroes. "I didn't really think about it," "I don't think of myself as a hero," "I was just focused on what needed to be done."

Their remarks are usually humble, usually speak of automatic reaction. Many, such as Meis, don't even want to speak to the media.

Researchers Selwyn Becker and Alice Eagly said in the journal American Psychologist that heroism is not only noble risk-taking, but also something selfish, a way to ensure status.

They are the scientific researchers, but my gut tells me that most heroes are not out for selfish glory or status. They just seem somehow wired differently. Furthermore, I believe that many people have a little bit of hero inside them, and sometimes all it takes is one person to get the ball rolling, as was the case in Seattle, where a gunman had already killed one person, wounded two others and was in the process of reloading.

I don't think heroes have time to weigh the morality of their actions at the time. I suspect their values are already so deep-seated that they automatically act on them when faced with a morally challenging situation.

Psychiatrist Deane Aikins says heroes often cultivate social bonds before and after the crisis. While this is true in organizations like the military or police, and exemplified many times in feats on the job, what about those everyday heroes — the ones who act for the benefit of strangers?

I love all heroes, because any time a human being does something good, I rejoice. But to me, these humans are the ones who give me faith in humanity, the world, God, the universe and everything.

The other day, I witnessed a bad motorcycle accident. For a second, the world just froze. People sat in their cars, stunned. Nothing happened for about 30 seconds. Then, one man got out of his car and rushed over to the motorcycle rider. Soon, a woman rushed over with her cellphone. Then another person ... and another. The rider was soon surrounded: one person down on the ground with him, one directing traffic, one on the phone.

That first man was a true hero. And then the woman became a hero because of the first man. And then they were all heroes.

By the time I was able to make it to the scene of the accident, I drove up next to the first man and asked how I could help. "We got it," he said, clearly shaken. "You're a hero," I said. He looked at me, confused. "Why?" And then he walked off to the task at hand.

Today is D-Day, and while we remember the lives of many heroes on that day, and read plenty of stories that honor them, and while we continue arguing about whether Bowe Bergdahl is a hero or a villain, I want to take a moment.

I want to honor the heroes for whom there are no days of honor, no ceremonies, no medals, no recognition. These heroes are all around you, and they are complete strangers. They won't reveal themselves until something very bad is happening. And then you will see something amazing. You will see the very definition of humanity.

Laurel Dalrymple is an editor and writer for NPR.org. You can follow her on Facebook atfacebook.com/laurelmdalrymple

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