I’m an arrow in the quiver.
I know what I can do when the time comes, in a general sense. However, I have not yet seen the target, so I have no idea what the specifics might be.
No, there is no rational explanation. But as surely as I live and breathe, I know the parable is accurate: I’m an arrow in the quiver. I’m waiting to be launched, but the battle is not yet begun.