The human brain is an amazing computer, but now and then it seems to enjoy playing tricks on its owner, such as with déjà vu.

Déjà vu, we've all experienced it. It's French for "already seen." It feels weird when it happens. You find yourself in a situation — a pre-op conversation with a co-worker or a sudden change of surgical plans, for example — that you are certain you've lived through at least once and maybe repeatedly before. A new situation, that is. Having to make a run from the OR for supplies someone forgot to pull for a case doesn't count.

Mind games
What causes this phenomenon? (The déjà vu, not the missing supplies.) There are a number of theories. Some scientists speculate that it's the result of a momentary delay in the arrival of sensory information at the brain, or the overlapping of short-term and long-term memory. Some non-scientists suggest it's a pre-cognitive event or the consciousness's separation from the body to visit other worlds, of which there are an infinite number. Great. As a traveling nurse, it's bad enough to wake up and have to remember what state I'm in. Now my consciousness might be out getting me into trouble in other realities.

A related phenomenon is known as déjà visité ("already visited"), and it's said to be a less-common experience, though perhaps not for those who've worked in more than a few surgical facilities. You walk into a place you've never been to before, yet it seems so familiar that you're able to navigate it effortlessly with a knowledge that is impossible for you to have. You don't have to be a traveling nurse to have experienced this, although for permanent staffers, perhaps jamais vu ("never seen") is more likely. That's when something you've seen or done or repeated more times than you can count suddenly seems totally foreign to you. (The scientists say this might be a symptom of mental fatigue.)

Even more puzzling, though, is when the familiarities aren't just appearing in your mind but before your eyes. Among traveling nurses, "the more things change, the more they stay the same" is the truth. But how is it that I can start a new assignment and meet someone who looks identical to a nurse I worked with 5 years ago and 5 states west? I've heard it said that everyone has a twin roaming around out there. Personally, I'd love to have a twin. But this would open the door, of course, to the nightmarish possibility that I'd someday have to work again with, oh, let's call him Dr. Booger. Or, in the worst-case scenario, a roomful of Dr. Boogers, who might not only look but also act the same.

Past leaking into present?
Déjà vu, we've all experienced it. A friend from West Virginia says we have déjà vu because we live our lives over and over again until we get them right. After we do this a number of times, sometimes the past events leak a little (kind of like incontinence) into the present moment.

I look on the bright side. No matter how many errors and embarrassments I've committed this time through, maybe I at least avoided the really major ones I stepped in last time around. Like, for example, not choosing surgical nursing as a career. Whether I'm working in a familiar OR, or one that only my consciousness has visited before, I love what I do. And while some days are better than others, there's always something new to see, among everything that I've already seen.