First, I would like to wish all of you Libras out there at happy birthday! It’s your time 🙂
Now, on the topic of birthdays, I present to you the “birthday problem.” If you’ve ever taken statistics, you may already be familiar with this fun phenomenon. Simply, it is stated that in a room of just 23 people, the probability that two people share a birthday is 50%, and in a room of 70 people, the probability that two people share a birthday is 99.9%. Because there are 365 (or 366) days in a year, we would expect that we would need a much larger sample of people to have such coincidences. However, this problem only seems like a conundrum, because we are human and kind of self-centered.
If we ask what is the probability that I will have the same birthday as someone else, then the answer is that there is a .274% chance (1/1 multiplied by 1/365) that I and one other person will share a birthday. However, what we are asking is, what are the chances that any of the 23 people will share a birthday. In this way, the first person has 22 chances of finding a pair, the second person, 21 chances, and so on. When we add up all of these chances (22+21+20…) we get 253 chances (representing more than half the year), making it much more likely that some person (instead of just “I”) will find a pair even in a relatively small group.
While this birthday problem is well-established, I have my own birthday problem that has zero to do with math and everything to do with our feelings about aging. Do you remember when you were excited to get older, Dear Reader? Did you feel this way about every birthday? Do you feel this way now? There are some ages that we dive headfirst into like 18 or 21, but there are others that we cautiously enter like a cold swimming pool such as 30, 40, 60, or any other round year. I’ve had mixed feeling about my birthday ever since I was a child. I remember feeling anxious about turning 10 years old (you know, “the big one zero”). Double digits — gasp! What does this mean? Is this the end of childhood? Do I no longer get toys on Christmas??
Do you remember how quickly doors used to open and close for you as a child? One year you’re too short to ride the big-kid roller coasters and the next year you’re being kicked out of kiddie land. Ten-year olds are too old for the McDonald’s PlayPlace, but are too young for PG-13 movies and to drive go karts. Childhood has a lot of mini milestones!
I am in my mid-20’s. I am a Libra too, so it is my birthday, and I will still—pretty much—be in my mid-20’s with the dawning of my new year. Huzzah! Decades from now, I know I will not remember my 20’s as ten discrete years, rather in two or three distinct periods marked by college, graduation, and other life events. Age probably isn’t the best mile marker. As adults, I feel that we tend to mark life with “before’s” and “after’s:” before a loved one died, after a child was born, before the breakup, after marriage, etc…. In this way, birthdays (at least to me) become less meaningful with age. I think the world (or at least Hallmark) agrees with this as there are plenty of birthday cards specifically for 6 and 10 year olds, but none for 42 and 78 year olds.
Regardless, we all have birthdays and hopefully celebrating another full year of life still means something to you! So, happy birthday to you, Dear Libras! Happy birthday to me! And, happy days to you all, Dear Reader!