To demonstrate this, we can just use this as example:
9/11 prompted the Federal Reserve to cut interest rates, which helped drive the housing bubble, which led to the financial crisis, which led to a poor jobs market, which led tens of millions to seek a college education, which led to $1.6 trillion in student loans with a 10.8% default rate. It’s not intuitive to link 19 hijackers to the current weight of student loans, but that’s what happens in a world driven by a few outlier tail events.