Am I really what I perceive?

At the beginning of Chapter 6, Steiner makes the following rather bold assertion:

Therefore I really am the things; not, however, "I" in so far as I am a percept of myself as subject, but "I" in so far as I am a part of the universal world process. The percept of the tree belongs to the same whole as my I. This universal world process produces equally the percept of the tree out there and the percept of my I in here.

In what sense am I the tree, the moon, the sun, the stars, the people I perceive?  This sounds rather mystical. 

But in fact Steiner is pointing to something the essence of which is not mystical and vague, namely thinking.

To know anything for me involves thinking, which I most definitely experience as my own activity through and through, which I do not need to theorise about or form mental images of - I already know it so intimately because I carry it out.  It is not out there or in here but I know it's something that I do and I know exactly what it is.

So in what sense am I really the moon?  Precisely in this sense, that to know the moon at all I must connect percepts to concepts in thinking.  This activity is not merely subjective but is a part of the universal world process.  The moon does not exist apart from thinking, thinking is an activity of my I, therefore I am the moon precisely to the extent that I know the moon.