Birthday Surprises

Why do people feel that it is a surprise and a coincidence for two people to have the same birthday? The fact of the matter is that it only takes 23 people in a room to have a 50/50 probability of two people having the same exact birthday in month and day.
This problem can be easily explained using basic probability. Assuming that all 365 days of the year have an equal chance to be someone’s birthday, we can determine how to arrive at the conclusion of 23 people. First, the chances of an event occurring and the chances that is does not occur always equal 1. Therefore, we can say this: The probability that the first...