Paradox of Non-Pursuit

There is this common saying that once you cease desiring a thing, you will then obtain it. A friend recently told me that I will finally have a girlfriend when I stop looking for one. This seems paradoxical. Take some other desire, like the well-being of your child. Then, some maniac who likes to see you suffer tortures your child because he will get the response desired from you. However, when he sees that once you become indifferent to your child's well-being, he stops torturing your child. So, what is the right thing here to do? In the same way, there is a sense in which pursuing marriage and pursuing a relationship is a good thing, like pursuing the well-being of your child is a good thing, and so the refusal to pursue that good is an immoral thing to do.

One difference that can be appealed to here is that one has a duty to your child, but not a duty to pursuing a relationship, so the dilemma doesn't exist in not wanting to want to be in a relationship (whoa...meta). Okay, then take a similar case. Say I desire the well-being of my garden. The more effort and love I put into it, the more it dies. Then, someone tells me that once I become indifferent (or maybe even hate) to my garden, then it prospers, because my hatred released some pheromone that plants thrive off. Being in the state of mind where I do desire my prosperous garden, would my ability to choose to discard that (if I could, somehow just choose) be rational? 

It makes me think of a case I heard some time ago, but I can't remember the context, but I feel it's relevant, so I'll give it a twirl. Say God tells you some truth, like, what the color of the sky is. And God says to you, I will instill in your mind this true belief, but I will give you a justification for it that is invalid or not true. What should you do? On one hand, you desire the pursuit of truth, but on the other, you don't want to do it the wrong way. You don't want bad reasons for good things. Or do you? I dunno.

Anyways, the situation is real. Maybe. Maybe if I stopped looking for a girlfriend, one will just kind of happen.