Running the numbers and learning the physics behind it will only confuse you. The only real way to explain this phenomenon is problembility.
Problembility is most simply the probability that whatever will cause you the most problems will happen to you. Often, these situations are unanticipated. For example, not thinking that in a city of 800,000 you are going to be driving by the one boy you're seeing with another boy in the car. Sometimes, there is an obvious sign. But always, there is a high level of problem and a low level of probability.
In further news, I am thinking of asking a statistician to run the numbers on some of my funnier situations. Stay tuned.