In the wake of the shootings at Virginia Tech, everyone was asking, “How could the tragedy have been prevented?”

The answer from various experts was that although gun regulation, better mental health services, beefed up security on campuses and less bullying might decrease violence, there is no way to prevent things like this from ever happening again.

Half way around the world suicide bombers continue to take lives. Here in the States, a demand for protection arose after consumers found that their spinach and even their pet food were tainted by toxins. In these cases, as with the shootings on the Virginia Tech campus, we can only hope to strengthen our protections in lieu of ever eliminating the danger.

Many middle class Americans I know seem obsessed with staying safe. For me, the symbol for this hyper-concern for safety is the existence of antibiotic wipes at the entrance of the River Forest Jewel so patrons can disinfect the handles of their shopping carts.

Here is why this is a problem.

I heard a piece on the radio two weeks ago by a guy who was arguing that the use of so many antibiotics in the home is ironically making Americans more vulnerable to serious infections. The man’s contention was that by preventing relatively benign, everyday bacteria from entering the body, our sterile environments are in effect making our immune systems lazy. The result is that when our bodies are invaded by a blitzkrieg of really tough germs, our body’s defenses are defenseless.

The point the speaker was making, I think, is that in a less than perfect world, being exposed to less than lethal doses of potentially difficult experiences might prepare us for responding well to lethal threats when they inevitably come our way.

I’ll give you an example. I went on my first canoe trip in the Boundary Waters Canoe Area when I was 15. I got sunburned, swatted swarms of mosquitoes and ate dehydrated food for 10 days. The worst part was portaging the 17-foot 70-pound canoe. During the first portage-half a mile long-I thought I was going to die.

The canoe trip was one of the most wonderful experiences of my life. I loved the beauty, the quiet and knowing what it feels like for my body to get stronger. I learned that sleeping on the hard ground and paddling against the wind was simply part of the package, the price I had to pay for a deeply satisfying, life enhancing experience.

Liviu Librescu, a 76-year-old professor at Virginia Tech, a Jew born in Romania and a survivor of the Holocaust, responded to Cho’s rampage of killing by holding the door to his classroom shut with his own body. His action bought enough time for several of his students to escape through a window. His life of hard knocks prepared him to do the courageous thing, the loving thing in the face of danger.

It is the duty of all who nurture children to protect them from danger. But maybe we are cheating them if we protect them from all harm. Felix Adler said, “The purpose of man’s life is not happiness but worthiness.” If you went to church on Good Friday as well as on Easter Sunday, you saw what Christians consider to be the model of true humanity trade in his safety for a life and death encounter with evil.

Tragedy is going to happen in our lives. Librescu knew what to do when it happened to him. While we do what is realistically possible to prevent another Virginia Tech tragedy from happening, let us prepare ourselves and our children to know what to do when it happens.