For those not familiar with the birthday problem, it is simply the question that:

“What is the chance of sharing your birthday with another person in a room of say 23 people?“

The answer for that specific number of people is around 50% chance. In the first instance, you might think that is pretty high, given there are 365 days in a year and only 23 people in the room. But actually the chance increase pretty quick (exponentially) and for a room of 40 people, there is almost 90% chance that two persons share their birthday!! This is a typical case for why human brain has hard time understanding exponential growth. Although, this post was supposed to be about my birthday, which is coming soon, and the fact that during my time working in Gothenburg (Sweden); I had a colleague with my exact birthday. And I mean exact to the year !! I was wondering what would be the odds of that happening and if you actually calculate it for any two persons, assuming the average human age of 73 years, it’s around 0.00375%. That is pretty low and it is kind of insane and cool that it actually happened to me. But I guess, it happened to all of us the day we were born. So would that actually make the probably equal to 100%? That’s the border between being statistical and sentimental I would say.