It's very simple math. You flip a penny once, and there is a 1-in-2 chance it will come up heads. You flip a coin twice, and there is a 2 to the 2d power (1-in-4) chance it will come up heads both times. Flip it three times, and there is a 2 to the 3d power (1 in 8) chance that Abe Lincoln will be smiling. By the time you've flipped the coin 20 times, you're up to a 1-in-a-million chance that the coin will land as heads each and every time. In Tom Stoppard's play Rosencrantz and Guildenstern are Dead, Guildenstern realizes that fate is guiding the coin as it lands the same way in over 100 tosses.
The simple heads/tails, yes/no, binary calculation underlies the routine of living. Orange juice, or none? Arrive at work early, or late? Will it rain, or not? Will a batter hit the ball, or strike out? Will this May be warmer or colder than the average May of the 20th century? Unlike the coin toss, some of these binary results aren't produced by pure chance; a person who forgot to pick up orange juice last night won't have any for breakfast, and a batter on steroids will hit a weak pitcher's ball.
This May was, in fact, warmer than the 20th century average May. It was the second warmest on record, calculates the National Oceanic and Atmospheric Administration. And - this is the scary part - it was the 327th month in a row (over 27 years) that a month has been warmer than the same month in the 20th century average. The odds of that happening are 2 to the -327th power, or 2.73046341 x 10 to the -98th power. For a bit of context, there are roughly 5 x 10 to the 20th power stars in the universe. Or, for those of us mathematically-challenged folk, the odds of that happening are REALLY, REALLY, REALLY LOW.
But, hey, it's just a coincidence, right? It's not like fate, or human activity, or weather on steroids, has a hand in any of this, right?