William Shakespeare, "Hamlet" said, "Assume a virtue if you have it not".
What I understood from this saying is this: When in imagination you assume the feeling of the wish fulfilled, ACT ON IT! And by so doing, you are mentally lifted up to a higher level.
When, through your persistence, this assumption becomes actual fact, you automatically find yourself on a higher level (that is, you have achieved your desire) in your objective world. Your assumption guides all your mentally rational and innermost thoughts towards its suggested end so inevitably that it actually dictates the events.
The drama of life is a psychological one and the whole of it is written and produced by your assumptions.
Learn the art of assumption, for only in this way can you create your own happiness.