The "I"

In section 16 of pp. 153-155, Kant discusses the idea that synthetic unity is necessary for perception by the "I," or the one creating this synthesis of a priori knowledge and objects through the understanding. Something I was wondering as I was reading through this section (note the "I" ...) was whether or not Kant thinks that these a priori knowledge and objects exist at all outside of the context of the "I", and, if so, of what use they are. It made me think a bit of Bacon's idea of practical philosophy and the idea that philosophy is fruitless if there isn't a practical application for it. Then again, I may be misunderstanding Kant entirely because he seems to write like a mis-ordered dictionary.