When I took statistics at Eastern Montana College, the instructor (in a class of perhaps 30 or so) asked what the probability was of two people in the same room having the same birthday. The consensus was about 1 in 365. (Let's just say there were 36 people in the room, making the math much easier.)
Given that figure, most would figure the chances were roughly 10%. WRONG. Once you get about 20 or so people together, the probability goes above 50% (if I remember correctly.)
He wagered that two in the room had the same, and each student called out their birthday, one by one, and sure enough before even half way through the class ... probably only about 10 or 15 in ... two had the same.
Thus is statistics.
I have a relative with the same birthday as me -- September 2nd.
My father, and the mother of my significant other, both had the same birthday -- April 15th.
I've got a great grandfather who both born and died on Christmas Day, albeit 75 years later -- December 25th.
In my Harrington heritage, which directly correlates to Miles City, my great grandmother, was the first of 13 siblings -- 6 girls in a row, then 7 boys in a row -- what are the chances of that?
And on it goes. Odds and probabilities aren't necessarily what you might think.