I overthink things to the point of inaction. I strive to find balance between meaningful forethought (First order consequences, If this then that) and meaningless abstraction. (Third and fourth order hypothetical consequences)

It's the difference between

You hit a pool ball, and it starts to carom off the sides of the table. In theory, that's a fairly simple system, almost a Newtonian system. Since you can know the force imparted to the ball, and the mass of the ball, and you can calculate the angles at which it will strike the walls, you can predict the future behavior of the ball. In theory, you could predict the behavior of the ball far into the future, as it keeps bouncing from side to side. You could predict where it will end up three hours from now, in theory.

And

But in fact, it turns out you can't predict more than a few seconds into the future. Because almost immediately very small effects-imperfections in the surface of the ball, tiny indentations in the wood of the table-start to make a difference. And it doesn't take long before they overpower your careful calculations. So it turns out that this simple system of a pool ball on a table has unpredictable behavior.