Today is the day several people I know have a birthday. Five, according to Facebook, which informs me that I knew four of those in high school, no less - what a remarkable coincidence! - and two of them were reasonably good friends with each other, enough to share a five-way birthday party with several other nearby May-birthday friends.
Yet while it's quite unusual to have to have a couple of close friends from the same circle with a May 23rd birthday, it's hardly unusual to have two friends share the same birthday. By the time you know 23 birthdays, the odds are better than even that you know two people with shared birthdays. A remarkable coincidence - but of course, you're special, and you probably had to go through around 250 friends to find one who shared YOUR birthday.
We are inclined to recognize patterns in life. It's a useful skill, one that serves us well every day of our lives, but we're not always good judges of statistical significance, so sometimes we recognize patterns that are in fact simply random noise. This is where superstitions come from, and those little errant beliefs that aren't quite rational. Rationally, I know that having an ice-cold draft from the bar won't improve my motor control, but I swear, it seems to improve my bowling from atrocious to merely terrible!
Once we've picked out a pattern, and consciously identified it, we start to become emotionally attached to them. We've invested time and effort in it; every time you wear your lucky underpants and make out with a cute boy, you've reinforced the idea that they're lucky in your mind. When you wear them out and go home frustrated, you focus on another cause - a black cat, maybe a friend causing drama, there was something out there that interfered with your lucky underwear.
Psychologists have found intermittent reinforcement works very well, which might explain not only gambling addictions, but how doggedly we hang onto our curious patterns; medical doctors have found that delusion is remarkably effective at influencing how our bodies work. And there, we've come full circle. Most of the false patterns we see in life don't cause us much harm, and some even help us cope with the varied vagaries of life.
And who knows? Maybe a beer does relax me enough to let my cerebellum handle everything; maybe I treat my friend Terry like a little sister because I share a birthday with her big brother; and maybe, just maybe, your lucky sock makes you run just a little bit faster. But if you look hard enough for a pattern, one will emerge; whether it means anything or not is another matter entirely.