A puzzle without a solution is nothing. A lock without a key is worthless.
Is it our dependence on the meaning, that we can never overcome this matrix of interlocking needs? Why can the lock not simply be, without a key as a necessity? Were it to be our understanding, for a lock to have meaning beyond its combination with a key, perhaps things would be easier. Perhaps not.
A lock by itself is an item, often included in doors or items which are supposed to keep something inside. You lock things, you wish to remain firmly in one place. But, what if it were not so? Imagine a lock, as said before, but just the lock, the lock without the need or necessity for a key. Wether or not you can "lock" something with it, is of no importance then. The lock by itself is its own worth. And for our understanding, it dictates the need to think outside of the standard trail. Outside of well known paths.