"....knowledge lying beyond experience. It can therefore have for its basis neither external experience, which is the source of physics proper, nor internal, which is the basis of empirical psychology. It is therefore a priori cognition, coming from pure understanding and pure reason."

What the context clues was telling about this quote was something that I was in the middle of truly understanding, I guess knowledge working with experience is what makes understanding and reason. I understood because in essence of experience something whether good or bad you gain wisdom, and learn what could have made something better or made something worse. That in my opinion is the experience of life.