It works a lot like hunches and intuition. You kinda know that you need to go somewhere, but usually not why or what's going to happen. Once you're there, you do what you do naturally, which ends up helping the situation and the reason for your being sent is clear.
In practice, this allows for all sorts of things that can't be attributed to mere coincidence. Out of all the bars in Seattle, you found the one owned by Sephora's character. You might decide to invite someone to go to the movies with you, only to find out that they needed your help and couldn't call for various reasons.
Several years ago RL, I gave someone a bandage while I was visiting his house for our weekly hangout. Later in the week, he cut himself, but he only had one bandage in the house: the one I gave him. That kind of thing can easily be dismissed as coincidence, but to the Faithful, it's proof of the divine.
When I played a wizard in another game earlier this year, I was allowed to have a crappy Nokia phone (which have a notable reputation of being practically indestructible) and just having to replace it VERY frequently. Whether our GMs want to allow such is a different question altogether.