The point of the first paragraph is simple, but it may not be a point we have taken in before now. We are accustomed, perhaps, to the idea that everything that happens to us in this world is something we chose. We may not have been conscious of choosing it (or, as Lesson 136 says, we may have chosen it consciously but very rapidly, and then instantly forgot the choice), but somehow each outer event is a picture of an inward choice. (By the way, even though many consider this a central idea in the Course, I can only find four mentions of it, this lesson being one of them. So it's there, definitely, but should not be regarded as central.)
What this implies, according to this paragraph, is that our will is incredibly powerful. We tend to think of our will as one small whisper in a world of roaring wind, but it's the other way around. The wind of our will is so all-powerful that it flattens everything in its path. And as you look around your world, that is exactly what you are seeing.
And that is the value, says this lesson, of accepting that "What happens is what I desire." It's not so that we can choose better conditions—win the lottery and bag the babe (or the hunk). It's so that we can accept that our power is so great that nothing can stand in its way. This acceptance, rather than allowing us to reshape the game board of earth, actually draws our mind toward the heavenly state, where our omnipotent will brings new spirit into being. That is the significance of the concluding sentence: "For thus am I led past this world to my creations, children of my will, in Heaven where my holy Self abides with them and Him Who has created me."
To get in touch with this idea, then, look around you, and imagine that each thing you look on reflects a choice you have made. Every little item and every little movement was put there by your power of decision. None of it is actually battling with you. You are too powerful for that. If there is an apparent battle, it only reflects your inner decision to battle with yourself. In a real sense, then, the world is your dream. All the images you see were put there by your mind. True, behind many of those images—the ones we call bodies—are minds that are every bit as powerful as yours. But they only show up in your dream with permission from you. They are only there because they have agreed to act out a part chosen by you.
Try to feel the power of this. This is your dream. You are in charge. It is you who rule your destiny. You are not an empty can skittering about on the freeway. You are the writer and director of the play.
Now realize that this is a tiny reflection of a much greater truth. This is a concrete mirror of a formless reality, a reality in which your will is infinite, in power and in scope. Nothing stands in its way. It rolls out of you like a mighty river without banks. And as it rolls forth, it does not produce images, dream symbols. It produces eternal beings. It leaves behind a kingdom of living minds.
So let the fact that you rule your destiny in this dream draw your mind to the formless realm beyond the dream, where your Self is ruler of the heavenly universe.
The prayer for this lesson is one of the more mystical-sounding prayers in the Workbook. It carries on the theme of the first paragraph by fusing your Self with God, in a way that is almost unique in the Course. This fusion adds to the sense of power and rulership we got from the first paragraph. Let me add some words and comments for the sake of clarification:
You, God, are the Self Whom You created as your Son,
the Son who is creating like Yourself and One with You.
My Self, which rules the heavenly universe,
is nothing but Your Will in perfect union with my will,
which in turn can but offer glad assent to Your Will,
that Your Will may be extended to all its creations, which are but Itself.