Pi describes the circumference of a circle to its diameter. That relationship then can be said to describe "all knowledge where the circle is involved". The Greeks decided that relationship never ended in the how they went about defining PI. Ouroboros biting its tail and all that. You could argue, though, that there is a definite beginning and a definite ending at a given point on the circle. Some of that, of course, depends on where you start, but that's another story.

Matthew was an accountant. "None had risen higher" than John, and John was the fellow who Baptized Messiah. The culmination then of all knowledge up to that point was to be found in John, who was preparing the way for Messiah. Later John takes this further, and creates an entire Revelation, which makes the "accounting" of Matthew complete.

Therefore, the construct is pointing to the "Head of John" from a mathematical perspective. (A head is a kind of circle, after all)