There is a scientific study on why your headphones get tangled in your pocket.
And with this, scientists have officially run out of things to research. Kidding aside, the study actually identified 120 different types of knots that happen inside your pockets.
What's worse, in over 3400 different trials, they found that the probability of a knot being formed in your pocket is incredibly high, and the knots will be formed within seconds! Check out the source for more info. There's a great deal of complex knott-math and scientific analysis that has gone into this.