, by nature
intended), are antisocial
Go into the woods and grab a bunch of sticks together. You'll notice that they will all be unique and may be very different in characteristics such as length, width, and color.
Throw them on the ground, and they will flip and roll and bounce apart from each other.
This is why sticks are not generally very productive things when left to their own devices.
But when one forces a group of sticks to lie together, in the same direction, next to or on top of one another, for such purpose as, for example, to hide a geocache underneath them, they become much more practical and powerful than their normal, unruly brethren. They become Kings Among Sticks.
This is why parallel sticks rule.
But seriously. The "parallel sticks rule" is a common geocaching clue. Many people will try to cover up a partially exposed geocache in the woods with natural plant and other debris (though caches should almost never be buried).
A common method is to take a bunch of sticks, and pile them on top of the cache to obscure it. The problem (or perhaps deliberate benefit to other cachers) is that usually these sticks are carefully placed next to or on top of one another, in parallel.
However, as our story illustrates, sticks do not normally fall or otherwise gather themselves in such a deliberately, logically and geometrically arranged fashion.
Therefore if you are looking for a cache in the woods, and you happen upon a pile of sticks that are lying in parallel, you have probably found it.
This is the parallel sticks rule.