By our very existence on earth, our species has proven that avoiding injury is an excellent survival tool. We tie our shoelaces to avoid falls. We don’t run with scissors. We wear condoms or abstain from sex altogether. (Although too much abstinence is counterproductive to survival.) We do all these things and more because over the millennia such habits have ensured the survival of our species. Thanks to a combination of technology, wisdom, and experience, there’s no safer place in history than 21^st Century earth.

In spite of our overall survivability, risk is a fact of life and something all humans are forced to face. We often glamorize risk-taking behavior, rewarding daredevils like Johnny Knoxville and Evel Knievel with pop culture cachet as a reward for their lost blood and shattered bones. Yet even without the promise of fame, humans seem willing to trade some of our security for pleasure…even when it’s painful or if the pleasure payoff is a few steps removed. This begs the question—are we all masochists?

An easy example that many humans can likely relate to is the pain of an intense workout. We’ve all heard the mantra of “no pain, no gain” and to some degree, it’s a provable theorem. It takes repeated, intense effort to see physical improvements from our workouts, but aching muscles and general discomfort can be found with a quick jog down the street. While these efforts are likely to improve our health in the long term, it can be awfully hard to remember that while we’re sweating. Whether it’s the hundredth push-up or the last leg of a 5-kilometer run, perseverance pays off. What we sacrifice in comfort, we gain in health…I’ll call that a fair trade.

This counterintuitive behavior struck me another way on a recent bike ride. I’m not being figurative here; I lost a fair bit of skin to the hungry aluminum teeth of my pedals, and it hurt. But here’s the funny part…it hurt in a strangely good way. The combination of dirt, blood, sand and sweat wasn’t anesthetic by any stretch of imagination. Sure, my shin had swollen into something like a Twizzler and was bleeding from a handful of newly-installed holes, but it didn’t matter much while blasting down the Mala Compra mountain bike trail. I’d earned it…with friends, doing something I enjoy in nature. What we sacrifice in health, we gain in joy, and that’s a fair trade, too.

A dirt-caked wound, even a relatively minor one like my ordeal on two wheels, might have been fatal without the benefit of modernized medicine. With the benefit of medicine in mind, I’ll reveal my very favorite self-inflicted wound—voluntary blood donation. Although the simple stick of a hollow needle at the hands of a professional doesn’t really hurt much, it’s a pretty substantial sacrifice.

The single pint given in a typical donation represents about 10 percent of the total blood volume in an average adult, and it will take some time for your body to recover. During that time, your body is forced to work harder to accomplish the tasks that blood is famous for doing- moving oxygen to muscles and cells, fighting illness and infections, and even hormone distribution are all more challenging for a short time after donation. However, considering that a single accident victim could need 100 pints in order to stave off death, or that a single donation could save the life of up to three others, it’s a pale comparison. Depending on the type of donation, our bodies recover in a matter of days. For almost no sacrifice at all, some other human gets to live. That’s no trade at all—it’s a gift for both of us.